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Article

Improving Selected Chemical Properties of a Paddy Soil in Sabah Amended with Calcium Silicate: A Laboratory Incubation Study

by
Ivy Quirinus Chong
1,
Elisa Azura Azman
2,*,
Ji Feng Ng
3,
Roslan Ismail
4,
Azwan Awang
1,
Nur Aainaa Hasbullah
1,
Rosmah Murdad
5,
Osumanu Haruna Ahmed
6,*,
Adiza Alhassan Musah
7,8,
Md. Amirul Alam
5,
Normah Awang Besar
9,
Nor Elliza Tajidin
2 and
Mohamadu Boyie Jalloh
1,*
1
Crop Production Programme, Faculty of Sustainable Agriculture, Universiti Malaysia Sabah, Sandakan Branch, Locked Bag No. 3, Sandakan 90509, Malaysia
2
Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Malaysia
3
Department of Crop Science, Faculty of Agriculture Science and Forestry, Universiti Putra Malaysia Bintulu Sarawak Campus, Bintulu 97008, Malaysia
4
Department of Land Management, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Malaysia
5
Horticulture and Landscaping Programme, Faculty of Sustainable Agriculture, Universiti Malaysia Sabah, Sandakan Branch, Locked Bag No. 3, Sandakan 90509, Malaysia
6
Faculty of Agriculture, Sinaut Campus, Universiti Islam Sultan Sharif Ali, Km 33 Jln Tutong Kampong Sinaut, Tutong TB1741, Brunei
7
Department of Business Management and Law, Faculty of Business Management and Professional Studies, Management and Science University, University Drive, Off Persiaran Olahraga Section 13, Shah Alam 40100, Malaysia
8
Graduate School of Management, Post Graduate Centre, Management and Science University, University Drive, Off Persiaran Olahraga Section 13, Shah Alam 40100, Malaysia
9
Faculty of Tropical Forestry, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
*
Authors to whom correspondence should be addressed.
Sustainability 2022, 14(20), 13214; https://doi.org/10.3390/su142013214
Submission received: 4 September 2022 / Revised: 21 September 2022 / Accepted: 30 September 2022 / Published: 14 October 2022
(This article belongs to the Special Issue Soil Fertility and Plant Nutrition for Sustainability)
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Abstract

:
In Malaysia, the main constraints of rice yield and productivity are infertile soils and poor management practices because these soils are characterized by low pH, low nutrient availability, low organic matter, and high exchangeable Al and Fe ions, due to high rainfall and hot temperatures. Thus, an incubation study was conducted to determine the optimum amount of calcium silicate (HmbG brand) to improve the soil pH, electrical conductivity (EC), exchangeable Al, available P, and cation exchange capacity (CEC) of a paddy soil in Sabah, Malaysia. The Kelawat series (Typic Dystrudept) soil was incubated with calcium silicate at the application rates of 0 (T1), 1 (T2), 2 (T3), and 3 t ha−1 (T4) using a Completely Randomized Design (CRD) in triplicates for 30, 60, 90, and 120 days. The calcium silicate used significantly improved soil pH because of the release of SiO44− and Ca2+ ions, which neutralized and immobilized H+ ions. Furthermore, the neutralizing effects of the amendment impeded Al hydrolysis by up to 57.4% and this resulted in an increase in the available P in the soil by 31.26% to 50.64%. The increased availability of P in the soil was also due to the high affinity of SiO44− to desorb P from soil minerals and it is believed that SiO44− can temporarily adsorb exchangeable base cations such as K+, Ca2+, Mg2+, and Na+. Moreover, applying calcium silicate at 3 t ha−1 improved soil CEC by up to 54.84% compared to that of untreated soils (T1) because of increased pH and the number of negatively charged sites. The most suitable application rate of the calcium silicate was found to be 3 t ha−1 (T4). These findings suggest that calcium silicate can improve soil productivity and agronomic efficiency in rice farming. Greenhouse and field trials are necessary to ascertain the effects of the recommended treatments of this incubation study on soil productivity, rice growth, and yield.

1. Introduction

Rice is considered a staple food in many countries around the world. It is a staple food in Malaysia, as it is consumed by Malaysians in the forms of cooked rice, glutinous rice, and many other rice-based food products. According to Che Omar et al. [1], the annual consumption rate in the year 2016 was 80 kg of rice per person and this was equivalent to approximately 26% of the total caloric intake per day. In the same year, the average expenditure on rice consumption every month was 44 Malaysian Ringgit per household in Malaysia, where the households in the state of Sabah spent the most at 73 Malaysian Ringgit per month, whereas households in Perlis spent the least (13 Malaysian Ringgit per month). The increasing population in Malaysia, from 2016 (approximately 31.7 million) to 2020 (approximately 32.7 million), suggests that rice production should be increased in order to maintain the self-sufficiency rate (SSL) and food security [2,3]. However, rice production in Malaysia has not been increasing progressively, but rather shows a decreasing trend from 2016 (1,766,115 metric tonnes) to 2020 (1,512,709 metric tonnes) [4]. Che Omar et al. [1] opined that the implementation of proper farm management practices was one of the ultimate challenges to increase rice production.
In the tropics, rice crop yield and productivity are constrained by infertile soils, which are characterized by low pH, low essential nutrients availability, low cation exchange capacity (CEC), and low organic matter content. This is because the prevailing high rainfall and hot temperatures expedite the leaching of base cations such as potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) resulting in reduced soil pH and the replacement of exchangeable aluminium (Al), iron (Fe), and hydrogen (H) [5,6]. This not only detrimentally influences the availability of essential nutrients in the soil, such as nitrogen (N), phosphorus (P), and potassium (K), but also impairs nutrient uptake by rice plants because of injured and impeded root systems due to extensive soil acidity [7]. Furthermore, the intensive use of acidifying fertilizers such as urea and Triple Super Phosphate (TSP) causes soil acidification because of the release of H ions during nitrification and phosphorus-fixation processes [8,9,10].
Many innovations and products have been introduced to overcome the problems of poor soil productivity in rice farming. Slash-and-burn is one of the practices conventionally adopted by the farmers to remove leftover plant residues wherein the resulting ash is incorporated into the soils for nutrient cycling [11]. However, the in-situ burning of rice plant residues causes environmental pollution, the loss of biodiversity, and adverse effects to human health because burning emits carcinogenic and toxic gaseous compounds into the environment [12,13]. Furthermore, the continuous slash-and burn activities do not significantly increase rice grain yield, but rather, adversely affect soil fertility because of reduced soil pH and macronutrient availability (P, K, Ca, and Mg), in addition to increasing soil Al hydrolysis and the release of H ions [11,12]. The use of organic amendments such as chicken litter biochar and crude humic substances has also been extensively studied and introduced to improve soil and rice productivity in rice farming practices [14,15,16]. However, the performance of the organic amendments can be influenced by the raw materials used, variations in the number of functional groups, the slow release of nutrients due to recalcitrant properties, and the handling methods used during production [17,18,19,20]. To fix these problems, farmers’ adoption of the use of liming materials, which have high neutralizing ability and solubility, such as calcium silicate, is worth considering to improve soil pH and base cation saturation, and to reduce exchangeable Al and Fe in addition to increasing the nutrient holding capacity of the soil.
There is currently a dearth of information on the use of calcium silicate to improve soil pH, EC, available P, and CEC in relation to the suppression of the exchangeable Al of the paddy soil referred to as the Kelawat series (Typic Dystrudept) from Kampung Sangkir, Kota Belud, Sabah, Malaysia. The question of the right amount of calcium silicate to improve soil pH, EC, available P, and CEC in relation to the suppression of exchangeable Al in the paddy soil remains unanswered. Answering this research question is necessary because calcium silicate (Ca2SiO4) is a liming material or fertilizer which dissolves rapidly in water and releases exchangeable calcium (Ca2+) and orthosilicate (SiO44−) ions to increase soil base saturation, mitigate soil acidity, and enhance the defence mechanism of rice plants against biotic and abiotic stresses via calcification [21,22,23]. The use of silicon-based materials as soil amendment in rice farming is gaining increasing attention because it significantly improves crop resistance against pest and disease attacks, reduces crop-lodging incidence, and promotes plant growth via silification [24,25,26]. Furthermore, the increased concentration of water-soluble silicon in soils improves soil productivity through structure stabilization, enhanced soil pH and P availability due to neutralization and mobilization by Si, impeded Al hydrolysis, and the increased number of negatively charged sites to adsorb more exchangeable base cations [27,28,29]. The novelty of this incubation study is to introduce this calcium silicate product, which dissolves and release nutrients rapidly, to enhance the productivity of wetland rice cultivation in Sabah, Malaysia. The combined use of calcium silicate and organic amendments in rice cultivation will help to overcome the slow release of nutrients due to its high solubility. This could also reduce the use of slash-and-burn practices by farmers. It is hypothesized that the application of calcium silicate can improve soil pH, EC, available P, and CEC in relation to suppressing exchangeable Al. This could improve the soil productivity and rice yields in Malaysia for improved socioeconomic status and livelihoods of local farmers. This will also contribute to the attainment of higher self-sufficiency rates and sustainable food security. Thus, the objective of this laboratory incubation study was to determine the right amount of calcium silicate to improve the soil pH, EC, exchangeable Al, available P, and CEC of Kelawat series (Typic Dystrudept) soil obtained from Kampung Sangkir, Kota Belud, Sabah, Malaysia.

2. Materials and Methods

2.1. Soil Sampling and Preparation

In this study, the paddy soil used was the Kelawat series, which is a Typic Dystrudept based on the USDA soil classification system [30]. It is commonly used to cultivate cash crops such as oil palm, cocoa, and wetland rice [31]. According to Paramananthan [31], the Kelawat series is an inceptisol, which is classified as a fine loamy soil. This soil type is siliceous because it is an accreting recent alluvium which forms on levees, floodplains, terraces, and crab mounds in tidal swamps. The isohyperthermic temperature regime of this soil indicates that the average temperature is 22 °C and above at 50 cm depth from the soil surface, and changes in temperature are less than 5 °C across the varying seasons. The yellowish colour of the soil indicates that this soil type is characterized by a deep and well drained profile. This results in low base cation saturation because it is prone to leaching and low nutrient holding capacity. The soil sample was collected in a rice field located at Kampung Sangkir, Kota Belud, Sabah, Malaysia with the geographical coordinates of latitude 6.4036° N and longitude 116.4506° E. The random sampling technique was used to collect the soil samples from an uncultivated rice field (dry condition) and the land area was approximately 1 hectare. Using a shovel, random spots were chosen to collect five composite soil samples weighing approximately 25 kg within a depth of 75 cm. The soil samples were kept in nylon gunny sacks and transported to the laboratory at Universiti Malaysia Sabah, Sandakan Branch, Malaysia. The soil samples were then broken into smaller clods and air-dried on a clean surface covered with a plastic sheet. Thereafter, the soil samples were ground using a soil grinder and sieved to pass a 2 mm sieve. The sieved soil was bulked and mixed thoroughly for homogenization. The bulked soil was stored in zip-lock plastic bags prior to initial characterization and the laboratory incubation study. The brand of calcium silicate used in this study was HmbG.

2.2. Soil Initial Characterization

For measurements of soil pH and electrical conductivity, the soil suspension was prepared by mixing the sieved soils with distilled water at a ratio of 1:2.5 and 1:4, respectively, followed by shaking at 150 rpm for 30 min using an orbital shaker. Then, the experimental units were left to stand for an hour. Thereafter, the soil pH was determined using a digital pH meter, whereas soil electrical conductivity was determined using an EC meter [32]. Exchangeable Al3+ in the soil was extracted using 1 M KCl and determined using the acid–base titration method described by Rowell [33]. Available P in the soil was extracted using Mehlich’s No. 1 double solution (0.05 M HCl + 0.025 M H2SO4) in a ratio of 1:4 (soil: double acid), followed by molybdenum blue colour development method and measurement using Ultraviolet–Visible Spectrophotometry (UV-VIS) at a wavelength of 882 nm [34,35]. Soil CEC was determined using the leaching method described by Cottenie [36].

2.3. Soil Incubation Study

The soil incubation study was conducted for 120 days in the Soil Science Laboratory at the Faculty of Sustainable Agriculture, Universiti Malaysia Sabah, Sandakan, Sabah, Malaysia. A 500 g sample of sieved soil was weighed using an electronic balance for each replicate and kept in a plastic container. The application rates of calcium silicate were fixed at the recommended rates of 0 (T1), 1 (T2), 2 (T3), and 3 (T4) t ha−1 [37]. These recommended rates were scaled down per 500 g of soil at 0 g, 0.25 g, 0.50 g, and 0.75 g, respectively based on the assumption that one hectare of soil has a weight of 2.0 × 106 kg. The calcium silicate and soil samples were mixed thoroughly. The mixed soils were applied with distilled water and the water level maintained at 2 cm above the soil surface. The soil samples were covered with the lid of the containers to prevent excessive moisture loss. Each lid had two perforations to enable good aeration. The soils were then incubated for 30, 60, 90, and 120 days for each of the four treatments and replicated three times per batch. The experimental units were arranged using a Completely Randomized Design (CRD). The total number of experimental units for the incubation study was 48 (4 treatments × 3 replicates × 4 sampling times). At the end of incubation, the soil samples were air-dried, manually crushed, and sieved to pass a 2 mm sieve, for chemical analyses using the aforementioned procedures, which included soil pH, EC, exchangeable Al, available P, and CEC. Details of the treatments evaluated are summarized in Table 1.

2.4. Statistical Analysis

The collected data were subjected to a normality test to determine if the data were normally distributed. Thereafter, Analysis of Variance (ANOVA) was used to determine treatment effects, followed by Fisher’s Least Significant Difference (LSD) for mean comparison at p ≤ 0.05. The statistical software used was Statistical Analysis System version 9.4.

3. Results and Discussions

3.1. Initial Chemical Properties of the Paddy Soil

The initial chemical properties of the sampled Kelawat series (Typic Dystrudept) soil are summarized in Table 2. It is a neutral soil with a pH of 7.1 and the exchangeable Al was low with a value of 0.032 cmol (+) kg−1. According to Rahman et al. [38], when soil pH is less than 5.5, the exchangeable Al in the soil might exceed the toxicity threshold of 0.80 cmol (+) kg−1 and undergo Al hydrolysis, which can significantly impede crop growth and soil productivity. Complete Al hydrolysis produces one mole of Al3+, and this reaction releases three moles of H+ to further decrease the soil pH [39,40]. The EC of the Kelawat series is 0.028 cmol(+) kg−1; thus, this soil type is classified within non-saline salinity class (0 to 2 dS m−1). The soil CEC of the Kelawat series was 7.60 cmol (+) kg−1. This was because the soil had a deep and well-drained profile, which resulted in low base cation saturation and nutrient holding capacity [31]. The available P in the soil of the Kelawat series is considered low with a value of 4.600 mg kg−1. According to Dobermann and Fairhurst [41], a soil is considered as deficient in available P when it is less than 5 mg P kg−1. The paddy soil in Kota Belud is thus considered to be greatly deficient in available P in the soil, which implies that the application of phosphorus-based fertilizers is essential to improve available P in the soil.

3.2. Effects of the Application of Calcium Silicate on Soil pH

The application of the calcium silicate significantly increased soil pH in water at 60, 90, and 120 days of incubation, except for 30 days of incubation (Figure 1). At 60 days of incubation, T4 had significant higher soil pH in water (6.10) compared with T1 (5.84). The soil pH in water of T2, T3, and T4 was significantly higher than that of T1 (6.21) at 6.33, 6.52, and 6.55, respectively, at 90 days of incubation. However, at 120 days of incubation, only T2 and T3 had significantly higher soil pH in water at 6.33 and 6.30, respectively, compared with T1 (6.19). The slight fluctuations in soil pH throughout the 120 days of incubation was due to the high soil buffering capacity, which releases reserved H ions to reach chemical equilibration in the soil solution. For example, at 30 days of incubation, the insignificant change in soil pH in water among the treatments could be attributed to the high pH buffering capacity and neutral pH of the paddy soil. High pH buffering capacity indicates that the paddy soil has a high ability to resist drastic pH change when acid or alkaline substances are added. The silicate ions released via the dissolution of calcium silicate can neutralize the free H ions in the soil solution. This reaction causes the release of reserve H ions from exchangeable sites in the soil to maintain the equilibration of H ions in the soil solution [42]. This resulted in the insignificant changes in soil pH among the treatments at 30 days of incubation. Ning et al. [29] also revealed that large amounts of H and Al ions are adsorbed at the exchangeable sites in the soils with neutral pH; thus, the soil pH did not change significantly after the application of calcium silicate at 30 days of incubation.
The significant increase in soil pH at 60, 90, and 120 days of incubation was due to the continued dissolution of the calcium silicate which increased the adsorption of silicate ions at the exchangeable sites of the paddy soil. The dissolution of calcium silicate releases orthosilicate ions (SiO44−) into the soil solution and transforms it into a monosilicic acid (H4SiO4). This transformation also releases four hydroxide (OH−) ions to neutralize free H ions in the soil solution, which results in increased soil pH in water [43]. Furthermore, according to Elisa et al. [37], the application of calcium silicate can increase the adsorption capacity of soil to hold more silicate ions, which results in a significant increase in soil pH over time. Moreover, the application of calcium silicate releases exchangeable Ca ions to increase soil pH and immobilize H ions. This finding is in consensus with that of Cai et al. [44] who reported that the addition of soil amendments with higher base saturation compared with the soil does not only increase soil pH, but also immobilizes H ions via exchange reactions between the soils and the amendments.

3.3. Effects of the Application of Calcium Silicate on Soil Electrical Conductivity

The effects of the treatments on the electrical conductivity of paddy soil at 30, 60, 90, and 120 days of incubation are shown in Figure 2. There was no significant difference in soil electrical conductivity among the treatments, regardless of incubation period. By definition, soil electrical conductivity refers to the measurement of the amount of soluble salt in the soil solution. The soil electrical conductivity increased from a range of 0.065 to 0.069 dS m−1 at 30 days of incubation to a range of 0.072 to 0.077 dS m−1 at 60 days of incubation, followed by a declining trend at 90 (0.047 to 0.054 dS m−1) and 120 days of incubation (0.030 to 0.041 dS m−1). This trend was due to the increase in soil CEC over time throughout the incubation study. This finding is comparable to that of Friedman [45], who opined that increased soil CEC reduces the concentration of soluble cations such as K+, Ca2+, Mg2+, and Na+ in the soil solution through adsorption at exchangeable sites, thus contributing to reduced soil electrical conductivity over time. This suggests that the addition of calcium silicate can improve the retention of soluble cations (K+, Ca2+, Mg2+, and Na+) over time. This finding is consistent with that of Ramos et al. [46], who reported that silicate rock powder can adsorb exchangeable base cations and contaminants in water bodies and soil solution.
Notably, the soil electrical conductivity did not exceed the soil salinity threshold of 4 dS m−1 at 30, 60, 90, and 120 days of incubation, but was within the salinity class of 0 to 2 dS m−1 (non-saline). According to USDA [47], when the soil electrical conductivity exceeds the threshold of 4 dS m−1, this will detrimentally affect soil productivity because of impeded crop growth and microorganism activities due to high salinity. Specifically, according to Dobermann and Fairhurst [41], the optimum soil electrical conductivity to produce desirable rice yield falls in the range of not more than 2 dS m−1. The findings suggest that the application rates of the calcium silicate used in this study are acceptable for rice cultivation.

3.4. Effects of the Application of Calcium Silicate on Exchangeable Aluminium in the Soil

Figure 3 shows the treatment effects on the exchangeable Al in the soil at 30, 60, 90, and 120 days of incubation. The results show that the exchangeable Al in the soil in this study, regardless of treatment and days of incubation, did not exceed the Al toxicity threshold of 0.8 cmol(+) kg−1, which can significantly impede crop growth [38,48]. The application of calcium silicate significantly reduced the exchangeable Al in the soil to 0.02 cmol(+) kg−1 (T3 and T4) compared with that for T1 (0.047 cmol(+) kg−1) at 30 and 90 days of incubation. At 60 days of incubation, the exchangeable Al3+ in the soils with an application rate of 3 t ha−1 (T4) was significantly reduced to 0.02 cmol(+) kg−1, compared with the soils with no application of calcium silicate (T1: 0.04 cmol(+) kg−1). Moreover, at 120 days of incubation, T3 revealed the lowest exchangeable Al3+ in the soil (0.02 cmol(+) kg−1) compared with that of T1 (0.047 cmol(+) kg−1). This suggests that the application of calcium silicate at the rates of 2 to 3 t ha−1 can ameliorate exchangeable Al3+ by up to 50% to 57.4% in the paddy soil used in this laboratory incubation study. These findings suggest that T3 (2 t ha−1) and T4 (3 t ha−1) are the most suitable treatments to reduce the amount of exchangeable Al in the Kelawat series used in this incubation study.
The significant suppression of exchangeable Al was due to the significant increase in soil pH, which transforms exchangeable Al into insoluble Al hydroxides through a precipitation reaction with OH ions [8,23,49]. The results of this study are similar to the findings of Ng et al. [50] and Ng et al. [51], who reported that the combined use of calcium- and silicon-based amendments can effectively suppress exchangeable Al in the soil by impeding Al hydrolysis over 120 days of incubation. This was due to their neutralizing ability, which can increase pH through the release of exchangeable Ca2+ and SiO44− concentrations. Furthermore, monosilicic acid can increase soil pH because of the strong adsorption of mobile Al ions on silica surfaces [28,52,53]. This implies that Al hydrolysis can be impeded from releasing more H ions because the chemical reaction between monosilicic acid and exchangeable Al forms insoluble and detoxified aluminosilicate and hydroxyl-aluminosilicate compounds [54]. These findings indicate that adding calcium silicate in the right amount can impede Al hydrolysis for up to 120 days and this could prevent the rice plants from being detrimentally affected by Al toxicity.

3.5. Effects of the Application of Calcium Silicate on Available P in the Soil

The treatment effects on available P in the soil at 30, 60, 90, and 120 days of incubation are presented in Figure 4. It shows that the application of calcium silicate at the rate of 1 t ha−1 (T2) significantly improved the amount of available P in the soil to 1.673 mg kg−1 by 31.26% compared with the available P in the soils without the amendment (T1: 1.150 mg kg−1) at 30 days of incubation. At 60 days of incubation, T2 significantly increased available P in the soil from a range of 33.35% to 50.64% to 2.330 mg kg−1, compared with T1 (1.453 mg kg−1), T3 (1.25 mg kg−1), and T4 (1.553 mg kg−1). This was due to the significant increase in soil pH, the suppression of P fixation by exchangeable Al, and P mobilization by Si from the exchangeable sites of the soil–Fe interaction. Opala et al. [55] and Laboski and Lamb [56] stated that the change in soil pH can stimulate the mineralization of organic P into inorganic P via decomposition by the soil microbes to release P from the exchangeable sites into the soil solution. The significant increase in soil pH can also unlock P fixed by exchangeable Al because of the transformation of exchangeable Al into Al hydroxides [23,39,40]. Moreover, the Si can increase P availability in the soil because of its higher affinity to mobilize P from the exchangeable sites of the Al, Fe, and Mn minerals in the soil [27,57,58].
However, P availability did not positively correlate with the application rates of the calcium silicate. Regardless of the number of days of incubation, the application of calcium silicate at the rates of 2 t ha−1 (T3) and 3 t ha−1 (T4) did not significantly increase available P in the soil. This could be due to the precipitation of available P in the soil by the increased concentrations of exchangeable Ca ions. When a soil is limed, the reaction between available P and exchangeable Ca ions produce insoluble Ca phosphate through precipitation, and this results in reduced available P in the soil [59,60]. Furthermore, the continued increase in exchangeable Ca ions further increases soil pH, which causes crystallization and prevents the dissolution of calcium silicate through the adsorption of available P on the surfaces of the calcium silicate [61]. In this study, T2 did not significantly improve soil P availability at 90 and 120 days of incubation. This finding suggests that prolonged applications of calcium silicate might decrease available P in the soil solution over time via fixation and crystallization. To fix this problem, the application of phosphorus-based fertilizers is essential, to saturate the soil with available P for crop uptake.

3.6. Effects of the Application of Calcium Silicate on Soil Cation Exchange Capacity

The soils amended with calcium silicate had significantly higher CEC compared with the untreated soils at 30 and 120 days of incubation (Figure 5). At 30 days of incubation, T4 exhibited a significantly higher soil CEC (13.00 cmol(+) kg−1) compared with T1 (7.767 cmol(+) kg−1). At 120 days of incubation, T4 demonstrated the highest soil CEC of 15.50 cmol(+) kg−1, followed by T3 (12.00 cmol(+) kg−1) and T2 (10.67 cmol(+) kg−1), whereas T1 had the lowest CEC of 7.00 cmol(+) kg−1. In other words, the addition of calcium silicate can significantly increase the soil CEC within the range 34.40% to 54.84%. These findings suggest T4 (3 t ha−1) as the most suitable treatment to improve the soil CEC of the Kelawat series in this incubation study.
The significant increment in soil CEC was due to the significant increase in soil pH and the number of negatively charged sites. Zhang et al. [42] and Aprile and Lorandi [62] opined that the soil CEC positively correlates with increasing soil pH when soil pH exceeds 6.5 because exchangeable acidity is considered negligible in terms of interfering with the effective CEC of the soil. Additionally, the deprotonation of functional groups in the soils due to the neutralization of H ions in the soil solution can increase the number of negatively charged sites to adsorb more divalent exchangeable cations such as Ca2+ and Mg2+ [63,64]. The increased amount of silicate minerals in the soils could also increase soil CEC because of the increased number of negatively charged sites [37]. These findings suggest that the application of calcium silicate at the right amount can improve soil nutrient retention and reduce leaching, because of increased CEC and pH buffering capacity. Our findings are comparable with those of Ng et al. [51], who reported that the combined use of Calciprill (CaCO3) and sodium silicate showed a positive correlation between soil effective CEC and pH buffering capacity because of improved soil nutrient retention. It is observed that the CEC of the soils treated with calcium silicate (T3 and T4) increases over time. This could be due to the saturation of monosilicic acid released through the dissolution of calcium silicate, which resulted in an increased number of negative charges on the soil adsorption surfaces [65]. This finding suggests that calcium silicate could improve the retention of soil essential nutrients (K+, Ca2+, Mg2+, and Na+), after which the continuous dissolution of the amendment would slowly release these retained nutrients over time for crop uptake.

4. Conclusions

The application of calcium silicate is an effective soil management approach to improve soil pH, available P, CEC, and the suppression of exchangeable Al. The increased soil pH was due to the release of SiO44− and exchangeable Ca ions to neutralize and immobilize H ions in the soil solution. The calcium silicate also suppresses Al hydrolysis, which temporarily improves available P in the soil. The higher affinity of Si to mobilize P from the adsorption sites of the soil minerals also increased P availability in the soil solution. The increased soil CEC was related to the significant increase in soil pH and the number of negatively charged sites, which could improve soil nutrient retention and pH buffering capacity. These findings suggest that this soil management approach can be adopted by farmers to mitigate soil acidity and increase nutrient availability for improving rice productivity and agronomic efficiency in infertile soils. The most suitable application rate of calcium silicate is 3 t ha−1 (T4) because it caused significantly higher soil pH, higher CEC, and lower exchangeable Al3+ in the soil. This incubation study provides fundamental information for further greenhouse and field trials to determine the effects of the recommended treatments on soil productivity and rice growth. Further greenhouse and field trials involving rice plants are necessary to validate these findings.

Author Contributions

Conceptualization, E.A.A., M.B.J. and O.H.A.; methodology, E.A.A., R.I. and R.M.; software, M.B.J. and M.A.A.; formal analysis, I.Q.C., E.A.A., J.F.N. and M.B.J.; investigation, I.Q.C. and J.F.N.; resources, A.A., N.E.T., and N.A.H.; writing—original draft preparation, I.Q.C., E.A.A., M.B.J. and O.H.A.; writing—review and editing, A.A.M., J.F.N., M.A.A., R.I., N.A.B., A.A. and N.E.T.; visualization, R.M., O.H.A. and A.A.; supervision, E.A.A., M.B.J., O.H.A. and N.A.H.; project administration, A.A., N.A.B., and A.A.M.; funding acquisition, E.A.A., N.A.B. and M.B.J. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by Universiti Malaysia Sabah (Grant Number: SLB0167-2018).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Acknowledgments

The authors would like to thank Universiti Malaysia Sabah for funding this research (Grant No: SLB0167-2018) and the collaboration with Universiti Putra Malaysia (Malaysia), Management and Science University (Malaysia), and Universiti Islam Sultan Sharif Ali (Brunei Darussalam).

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Che Omar, S.; Shaharudin, A.; Tumin, S.A. The Status of the Paddy and Rice Industry in Malaysia Key Findings of the Report; Khazanah Research Institute: Kuala Lumpur, Malaysia, 2019; ISBN 978-967-16335-7-1. [Google Scholar]
  2. Noorsuhaila, A.B.; Wan Abdullah, W.Y.; Shajarutulwardah, M.Y.; Norziana, Z.Z.; Noraini, S.; Badrulhadza, A.; Chong, T.V.; Mohd Hadi Akbar, B.; Arina Shairah, A.S. Evaluation Rice-duck Integrated Farming System on Rice Growth and Yield. Trans. Malays. Soc. Plant Physiol. 2020, 27, 146–152. [Google Scholar]
  3. Shah Zainal Abidin, I.; Haseeb, M.; Islam, R.; Wen Chiat, L. The Role of Rural Infrastructure, Labour and Capital Investment on the Rice Production in Malaysia. AgBioForum 2022, 24, 50–58. [Google Scholar]
  4. Department of Agriculture. Booklet Statistic Tanaman (Sub-Sektor Tanaman Makanan) 2021. Jabatan Pertananian Semenanjung Malaysia. Available online: www.doa.gov.my (accessed on 18 March 2022).
  5. Okalebo, J.R.; Othieno, C.O.; Nekesa, A.O.; Ndungu-Magiroi, K.W.; Kifuko-Koech, M.N. Potential for agricultural lime on improved soil health and agricultural production in Kenya. Afr. Crop. Sci. Conf. Proc. 2009, 9, 339–341. [Google Scholar]
  6. Fageria, N.K.; Baligar, V.C. Fertility management of tropical acid soils for sustainable crop production. In Handbook of Soil Acidity, 1st ed.; Rengel, Z., Ed.; CRC Press: New York, NY, USA, 2003; pp. 359–385. [Google Scholar]
  7. Alam, S.M.; Naqvi, S.S.M.; Ansari, R. Impact of Soil pH on Nutrient Uptake by Crop Plants. In Handbook of Plant and Crop Stress; CRC Press: New York, NY, USA, 1999. [Google Scholar] [CrossRef]
  8. Brady, N.C.; Weil, R.R. The Nature and Properties of Soils, 14th ed.; Pearson Prentice Hall: Upper Saddle River, NJ, USA, 2008. [Google Scholar]
  9. Ferguson, G.A.; Pepper, I.L. Ammonium Retention in Sand Amended with Clinoptilolite. Soil Sci. Soc. Am. J. 1987, 51, 231–234. [Google Scholar] [CrossRef]
  10. MacKown, C.T.; Tucker, T.C. Ammonium Nitrogen Movement in a Coarse-Textured Soil Amended with Zeolite. Soil Sci. Soc. Am. J. 1985, 49, 235–238. [Google Scholar] [CrossRef]
  11. Kikuta, M.; Yamamoto, Y.; Pasolon, Y.B.; Rembon, F.S.; Miyazaki, A.; Makihara, D. Effects of slope-related soil properties on upland rice growth and yield under slash-and-burn system in south konawe regency, southeast sulawesi province, indonesia. Trop. Agric. Dev. 2018, 62, 60–67. [Google Scholar]
  12. Da Silva Neto, E.C.; Pereira, M.G.; Frade, E.F.; Da Silva, S.B.; De Carvalho, J.A.; Dos Santos, J.C. Temporal evaluation of soil chemical attributes after slash-and-burn agriculture in the western Brazilian Amazon. Acta Sci.-Agron. 2019, 41, 1–10. [Google Scholar] [CrossRef]
  13. Tang, D.; Ho, K.A. Systematic Review of Slash-and-Burn Agriculture as an Obstacle to Future-Proofing Climate Change Microplastic and Nanoplastic Pollution View Project Biosorption of Heavy Metals from Aqueous Solution by Various Chemically Modified Agricultural Wastes: A review View Project. In Proceedings of the International Conference on Climate Change, Kuala Lumpur, Malaysia, 27–28 February 2020. [Google Scholar] [CrossRef]
  14. Perumal, P.; Ahmed, O.H.; Nik Muhamad, A.M.; Susilawati, K. Improving Rice (O. sativa L. cv. MR219) Yield and Nutrient Recovery Using Crude Humic Substances, Chicken Litter Biochar, and Clinoptilolite Zeolite. In In Proceedings of the 2nd Rice Research Colloquium, Universiti Putra Malaysia, Serdang, Malaysia, 22 April 2015; pp. 67–69. [Google Scholar]
  15. Maru, A.; Haruna, O.A.; Charles Primus, W. Coapplication of chicken litter biochar and urea only to improve nutrients use efficiency and yield of Oryza sativa L. cultivation on a tropical acid soil. Sci. World J. 2015, 2015, 1–12. [Google Scholar] [CrossRef] [Green Version]
  16. Maikol, N.; Haruna, A.O.; Maru, A.; Asap, A.; Medin, S. Utilization of urea and chicken litter biochar to improve rice production. Sci. Rep. 2021, 11, 1–20. [Google Scholar] [CrossRef]
  17. El-Naggar, A.; El-Naggar, A.H.; Shaheen, S.M.; Sarkar, B.; Chang, S.X.; Tsang, D.C.; Rinklebe, J.; Ok, Y.S. Biochar composition-dependent impacts on soil nutrient release, carbon mineralization, and potential environmental risk: A review. J. Environ. Manag. 2019, 241, 458–467. [Google Scholar] [CrossRef]
  18. Paramisparam, P.; Ahmed, O.H.; Omar, L.; Ch’ng, H.Y.; Johan, P.D.; Hamidi, N.H. Co-Application of Charcoal and Wood Ash to Improve Potassium Availability in Tropical Mineral Acid Soils. Agronomy 2021, 11, 81. [Google Scholar] [CrossRef]
  19. Johan, P.D.; Ahmed, O.H.; Omar, L.; Hasbullah, N.A. Phosphorus transformation in soils following co-application of charcoal and wood ash. Agronomy 2021, 11, 10. [Google Scholar] [CrossRef]
  20. Hamidi, N.H.; Ahmed, O.H.; Omar, L.; Ywih, H. Soil Nitrogen Sorption Using Charcoal and Wood Ash. Agronomy 2021, 11, 1801. [Google Scholar] [CrossRef]
  21. Daneva, A.; Gao, Z.; Van Durme, M.; Nowack, M.K. Functions and Regulation of Programmed Cell Death in Plant Development. Annu. Rev. Cell Dev. Biol. 2016, 32, 441–468. [Google Scholar] [CrossRef]
  22. Meena, M.C.; Meena, P.D.; Shukla, A.K.; Barman, M.; Meena, M.K.; Singh, P.; Kumar, A. Role of plant nutrients in enhancing productivity and managing diseases of oilseed Brassica. J.Oilseed Brassica 2016, 1, 1–20. [Google Scholar]
  23. Adnan, A.; Mavinic, D.S.; Koch, F.A. Pilot-scale study of phosphorus recovery through struvite crystallization—Examining the process feasibility. J. Environ. Eng. Sci. 2003, 2, 315–324. [Google Scholar] [CrossRef]
  24. French-Monar, R.D.; Rodrigues, F.A.; Korndörfer, G.H.; Datnoff, L.E. Silicon suppresses Phytophthora blight development on bell pepper. J. Phytopathol. 2010, 158, 554–560. [Google Scholar] [CrossRef]
  25. Pozza, E.A.; Pozza, A.A.A.; Dos Santos Botelho, D.M. Silicon in plant disease control. Rev. Ceres. 2015, 62, 323–331. [Google Scholar] [CrossRef]
  26. Wang, M.; Gao, L.; Dong, S.; Sun, Y.; Shen, Q.; Guo, S. Role of silicon on plant-pathogen interactions. Front. Plant Sci. 2017, 8, 1–14. [Google Scholar] [CrossRef] [Green Version]
  27. Schaller, J.; Faucherre, S.; Joss, H.; Obst, M.; Goeckede, M.; Planer-Friedrich, B.; Peiffer, S.; Glifedder, B.; Elberling, B. Silicon increases the phosphorus availability of Arctic soils. Sci. Rep. 2019, 9, 1–11. [Google Scholar] [CrossRef] [Green Version]
  28. Antonangelo, J.A.; Neto, J.F.; Crusciol, C.A.C.; Alleoni, L.R.F. Lime and calcium-magnesium silicate in the ionic speciation of an oxisol. Sci. Agric. 2017, 74, 317–333. [Google Scholar] [CrossRef] [Green Version]
  29. Ning, D.; Liang, Y.; Liu, Z.; Xiao, J.; Duan, A. Impacts of Steel-Slag-Based Silicate Fertilizer on Soil Acidity and Silicon Availability and Metals-Immobilization in a Paddy Soil. PLoS ONE 2016, 11, e0168163. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  30. Soil Survey Staff. Keys to Soil Taxonomy, 12th ed.; USDA-Natural Resources Conservation Service: Washington, DC, USA, 2014. [Google Scholar]
  31. Paramananthan, S. Malaysian Soil Taxonomy-Revised Third Version. In Agricultural Crop Trust and Param Agricultural Soil Surveys (M) Sdn; Bhd: Selangor, Malaysia, 2020; pp. 1–244. [Google Scholar]
  32. Peech, H.M. Methods of Soil Analysis. In Methods of Soil Analysis, Part 2: Chemical and Microbiological Properties; Norman, A.G., Ed.; American Society of Agronomy: New York, NY, USA, 1965; Volume 1, pp. 914–926. [Google Scholar] [CrossRef]
  33. Rowell, D.L. Soil Science: Methods and Applications, 1st ed.; Pearson Education Limited: London, UK, 1994. [Google Scholar]
  34. Mehlich, A. Determination of P, Ca, Mg, K, Na, NH 4. Test Methods Used in Soil Testing Division. 1953. Available online: http://www.ncagr.gov/agronomi/pdffiles/mehlich53.pdf (accessed on 4 November 2019).
  35. Murphy, J.; Riley, J.P. A modified single solution method for the determination of phosphate in natural waters. Anal. Chim. Acta 1962, 27, 31–36. [Google Scholar] [CrossRef]
  36. Cottenie, A. Soil and Plant Testing as a Basis of Fertilizer Recommendations; FAO Soils Bull. No. 38/2; FAO: Wallingford, UK, 1980. [Google Scholar]
  37. Elisa A., A.; Ninomiya, S.; Shamshuddin, J.; Roslan, I. Alleviating aluminium toxicity on an acid sulphate soils in Peninsular Malaysia with application of calcium silicate. Solid Earth Dis. 2015, 7, 2903–2926. [Google Scholar] [CrossRef]
  38. Rahman, Z.A.; Gikonyo, E.W.; Silek, B.; Goh, K.J.; Soltangheisi, A. Evaluation of phosphate rock sources and rate of application on oil palm yield grown on peat soils of Sarawak, Malaysia. J. Agron. 2014, 13, 12–22. [Google Scholar] [CrossRef] [Green Version]
  39. Thomas, G.W.; Hargrove, W.L. The Chemistry of Soil Acidity. Soil Acidity Liming 1984, 12, 3–56. [Google Scholar] [CrossRef]
  40. Ritchie, G.S.P. Role of dissolution and precipitation of minerals in controlling soluble aluminium in acidic soils. Adv. Agron. 1994, 53, 47–83. [Google Scholar] [CrossRef] [Green Version]
  41. Dobermann, A.; Fairhurst, T.H. Rice: Nutrient Disorders and Nutrient Management; IPI: Zug, Switzerland, 2000. [Google Scholar]
  42. Zhang, S.; Wang, R.; Cai, J.; Zhang, Y.; Li, H.; Huang, S.; Jiang, Y. Impacts of fertilization practices on pH and the pH buffering capacity of calcareous soil. Soil Sci. Plant Nutr. 2016, 62, 432–439. [Google Scholar] [CrossRef] [Green Version]
  43. Hinsinger, P.; Bolland, M.D.A.; Gilkes, R.J. Silicate rock powder: Effect on selected chemical properties of a range of soils from Western Australia and on plant growth as assessed in a glasshouse experiment. Fertil Res. 1995, 45, 69–79. [Google Scholar] [CrossRef]
  44. Cai, Z.; Wang, B.; Xu, M.; Zhang, H.; He, X.; Zhang, L.; Gao, S. Intensified soil acidification from chemical N fertilization and prevention by manure in an 18-year field experiment in the red soil of southern China. J. Soils Sediments 2015, 15, 260–270. [Google Scholar] [CrossRef]
  45. Friedman, S.P. Soil properties influencing apparent electrical conductivity: A review. Comput. Electron. Agric. 2005, 46, 45–70. [Google Scholar] [CrossRef]
  46. Ramos, C.G.; Hower, J.C.; Blanco, E.; Oliveira, M.L.S.; Theodoro, S.H. Possibilities of using silicate rock powder: An overview. Geosci. Front. 2022, 13, 1–11. [Google Scholar] [CrossRef]
  47. USDA. Soil Health Quality Indicators: Chemical Properties, Soil Electrical Conductivity. 2011. Available online: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/health/assessment/?cid=stelprdb1237387 (accessed on 13 April 2021).
  48. Ch’ng, H.Y.; Ahmed, O.H.; Nik, N.M. Biochar and compost influence the phosphorus availability, nutrients uptake, and growth of maize (Zea mays L.) in tropical acid soil. Pak. J. Agric. Sci. 2014, 51, 797–806. [Google Scholar]
  49. Moir, J.L.; Moot, D.J. Medium-term soil pH and exchangeable aluminium response to liming at three high country locations. Proc. New Zeal. Grassl Assoc. 2014, 76, 41–46. [Google Scholar] [CrossRef]
  50. Ng, J.F.; Ahmed, O.H.; Omar, L.; Jalloh, M.B.; Kwan, Y.M.; Musah, A.A.; Poong, K.H. Combined Use of Calciprill and Sodium Silicate Improves Chemical Properties of Low-pH Soil. Agronomy 2021, 11, 70. [Google Scholar] [CrossRef]
  51. Ng, J.F.; Ahmed, O.H.; Jalloh, M.B.; Omar, L.; Kwan, Y.M.; Musah, A.A.; Poong, K.H. Soil Nutrient Retention and pH Buffering Capacity Are Enhanced by Calciprill and Sodium Silicate. Agronomy 2022, 12, 219. [Google Scholar] [CrossRef]
  52. Sugama, T.; Pyatina, T. Effect of sodium carboxymethyl celluloses on water-catalyzed self- degradation of 200 °C-heated alkali-activated cement Cement & Concrete Composites. Cem. Concr. Compos. 2014, 55, 281–289. [Google Scholar] [CrossRef] [Green Version]
  53. Ramos, L.A.; Nolla, A.; Korndörfer, G.H.; Pereira, H.S.; De Camargo, M.S. Reactivity of soil acidity correctives and conditioners in lysimeters. Rev. Bras. Cienc. Solo. 2006, 30, 849–857. [Google Scholar] [CrossRef] [Green Version]
  54. Sposito, G. The Chemistry of Soils; Oxford University Press: Oxford, UK, 2008. [Google Scholar]
  55. Opala, P.A.; Okalebo, J.R.; Othieno, C.O. Effects of Organic and Inorganic Materials on Soil Acidity and Phosphorus Availability in a Soil Incubation Study. ISRN Agron. 2012, 2012, 1–10. [Google Scholar] [CrossRef] [Green Version]
  56. Laboski, C.A.M.; Lamb, J.A. Changes in soil test phosphorus concentration after application of manure or fertilizer. Soil Sci. Soc. Am. J. 2003, 67, 544–554. [Google Scholar] [CrossRef]
  57. Senn, A.C.; Kaegi, R.; Hug, S.J.; Hering, J.G.; Mangold, S.; Voegelin, A. Composition and structure of Fe(III)-precipitates formed by Fe(II) oxidation in water at near-neutral pH: Interdependent effects of phosphate, silicate and Ca. Geochim. Cosmochim. Acta 2015, 162, 220–246. [Google Scholar] [CrossRef] [Green Version]
  58. Koski-Vähälä, J.; Hartikainen, H.; Tallberg, P. Phosphorus Mobilization from Various Sediment Pools in Response to Increased pH and Silicate Concentration. J. Environ. Qual. 2001, 30, 546–552. [Google Scholar] [CrossRef] [PubMed]
  59. Karageorgiou, K.; Paschalis, M.; Anastassakis, G.N. Removal of phosphate species from solution by adsorption onto calcite used as natural adsorbent. J. Hazard. Mater. 2007, 139, 447–452. [Google Scholar] [CrossRef] [PubMed]
  60. Perassi, I.; Borgnino, L. Adsorption and surface precipitation of phosphate onto CaCO3-montmorillonite: Effect of pH, ionic strength and competition with humic acid. Geoderma 2014, 232–234, 600–608. [Google Scholar] [CrossRef]
  61. Tunesi, S.; Poggi, V.; Gessa, C. Phosphate adsorption and precipitation in calcareous soils: The role of calcium ions in solution and carbonate minerals. Nutr. Cycl. Agroecosyst. 1999, 53, 219–227. [Google Scholar] [CrossRef]
  62. Aprile, F.; Lorandi, R. Evaluation of Cation Exchange Capacity (CEC) in Tropical Soils Using Four Different Analytical Methods. J. Agric. Sci. 2012, 4, 278–289. [Google Scholar] [CrossRef] [Green Version]
  63. Liang, Y.; Nikolic, M.; Bélanger, R.; Gong, H.; Song, A. Effect of Silicon on Crop Growth, Yield and Quality. In Silicon in Agriculture; Springer: Dordrecht, The Netherlands, 2015; pp. 209–223. [Google Scholar] [CrossRef]
  64. Sdiri, A.; Higashi, T.; Chaabouni, R.; Jamoussi, F. Competitive removal of heavy metals from aqueous solutions by montmorillonitic and calcareous clays. Water Air. Soil Pollut. 2012, 223, 1191–1204. [Google Scholar] [CrossRef]
  65. Helling, C.S.; Chesters, G.; Corey, R.B. Contribution of Organic Matter and Clay to Soil Cation-Exchange Capacity as Affected by the pH of the Saturating Solution. Soil Sci. Soc. Am. J. 1964, 28, 517–520. [Google Scholar] [CrossRef]
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Figure 1. Mean soil pH in water in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1 and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
Figure 1. Mean soil pH in water in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1 and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
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Figure 2. Mean soil electrical conductivity in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1, and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
Figure 2. Mean soil electrical conductivity in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1, and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
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Figure 3. Mean exchangeable aluminium in the soil in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1, and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
Figure 3. Mean exchangeable aluminium in the soil in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1, and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
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Figure 4. Mean phosphorus available in the soil in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1, and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
Figure 4. Mean phosphorus available in the soil in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1, and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
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Figure 5. Mean soil cation exchange capacity in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1, and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
Figure 5. Mean soil cation exchange capacity in relation to the application of calcium silicate at 30, 60, 90, and 120 days incubation, where T1 is soil without calcium silicate (0 t ha−1), T2 is soil with calcium silicate at 1 t ha−1, T3 is soil with calcium silicate at 2 t ha−1, and T4 is soil with calcium silicate at 3 t ha−1. Different letters indicate significant mean differences using Fisher’s Least Significant Difference test at p ≤ 0.05. The error bars refer to the standard error of three replicates. Small letters, small letters with ’, small letters with ’’, and small letters with ’’’ indicate mean comparison at 30, 60, 90, and 120 days incubation, respectively.
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Table
Table 1. Details of the calcium silicate application rates in the laboratory soil incubation study.
Table 1. Details of the calcium silicate application rates in the laboratory soil incubation study.
TreatmentDescription (t ha−1)Application Rate (g 500g−1 Soil)
T100
T210.25
T320.50
T430.75
Table
Table 2. Selected chemical properties of the sampled Kelawat series (Typic Dystrudept) soil.
Table 2. Selected chemical properties of the sampled Kelawat series (Typic Dystrudept) soil.
Chemical PropertyValue Obtained
Soil pH7.1
Soil EC (dS m−1)0.028
CEC (cmol(+) kg−1)7.60
Exchangeable Al (cmol(+) kg−1)0.032
Available P (mg kg−1)4.600
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Chong, I.Q.; Azman, E.A.; Ng, J.F.; Ismail, R.; Awang, A.; Hasbullah, N.A.; Murdad, R.; Ahmed, O.H.; Musah, A.A.; Alam, M.A.; et al. Improving Selected Chemical Properties of a Paddy Soil in Sabah Amended with Calcium Silicate: A Laboratory Incubation Study. Sustainability 2022, 14, 13214. https://doi.org/10.3390/su142013214

AMA Style

Chong IQ, Azman EA, Ng JF, Ismail R, Awang A, Hasbullah NA, Murdad R, Ahmed OH, Musah AA, Alam MA, et al. Improving Selected Chemical Properties of a Paddy Soil in Sabah Amended with Calcium Silicate: A Laboratory Incubation Study. Sustainability. 2022; 14(20):13214. https://doi.org/10.3390/su142013214

Chicago/Turabian Style

Chong, Ivy Quirinus, Elisa Azura Azman, Ji Feng Ng, Roslan Ismail, Azwan Awang, Nur Aainaa Hasbullah, Rosmah Murdad, Osumanu Haruna Ahmed, Adiza Alhassan Musah, Md. Amirul Alam, and et al. 2022. "Improving Selected Chemical Properties of a Paddy Soil in Sabah Amended with Calcium Silicate: A Laboratory Incubation Study" Sustainability 14, no. 20: 13214. https://doi.org/10.3390/su142013214

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