Agronomy

1879 KiB

Open AccessArticle

Soil Tillage Systems and Wheat Yield under Climate Change Scenarios

by Pieranna Servadio, Simone Bergonzoli and Claudio Beni

Agronomy 2016, 6(3), 43; https://doi.org/10.3390/agronomy6030043 - 20 Sep 2016

Cited by 12 | Viewed by 5270

In this study, the effects of three different main preparatory tillage operations: ploughing at 0.4 m (P40) and 0.20 m (P20) depth and harrowing at 0.20 m depth (MT) were investigated. The tillage operations were carried out at two different times, as the soil water content increased over time from rainfall: (low, 58% (LH) and high, 80% (HH) of field capacity). Results obtained from the soil monitoring carried out before and after tillage showed high values of soil strength in terms of Penetration resistance and shear strength particularly in deeper soil layers at lower water content. During tillage, fossil-fuel energy requirements for P40 LH and P20 LH were 25% and 35% higher, respectively, with respect to the HH treatments and tractor slip was very high (P40 LH = 32.4%) with respect to the P40 HH treatment (16%). Soil water content significantly influenced tractor performance during soil ploughing at 0.40 m depth but no effect was observed for the MT treatment. The highly significant linear relations between grain yield and soil penetration resistance highlight how soil strength may be good indicator of soil productivity. We conclude that ploughing soil to a 0.20 m depth or harrowing soil to a 0.20 m depth is suitable for this type of soil under climate change scenarios. Full article

(This article belongs to the Special Issue Advanced Agronomy with Impact for Food Security)

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1068 KiB

Open AccessArticle

Synergistic Effects of Agronet Covers and Companion Cropping on Reducing Whitefly Infestation and Improving Yield of Open Field-Grown Tomatoes

by Stella Mutisya, Mwanarusi Saidi, Arnold Opiyo, Mathieu Ngouajio and Thibaud Martin

Agronomy 2016, 6(3), 42; https://doi.org/10.3390/agronomy6030042 - 19 Sep 2016

Cited by 19 | Viewed by 8187

Abstract

Tomatoes (Lycopersicon esculentum Mill) are one of the biggest vegetable crops in the world, supplying a wide range of vitamins, minerals and fibre in human diets. In the tropics, tomatoes are predominantly grown under sub-optimal conditions by subsistence farmers, with exposure to biotic and abiotic stresses in the open field. Whitefly (Bemisia tabaci Gennadius) is one of the major pests of the tomato, potentially causing up to 100% yield loss. To control whitefly, most growers indiscriminately use synthetic insecticides which negatively impact the environment, humans, and other natural pest management systems, while also increasing cost of production. This study sought to investigate the effectiveness of agronet covers and companion planting with aromatic basil (Ocimum basilicum L.) as an alternative management strategy for whitefly in tomatoes and to evaluate the use of these treatments ontomato growth and yield. Two trials were conducted at the Horticulture Research and Training Field, Egerton University, Njoro, Kenya. Treatments comprised a combination of two factors, (1) growing environment (agronet and no agronet) and (2) companion planting with a row of basil surrounding tomato plants, a row of basil in between adjacent rows of tomato, no companion planting. Agronet covers and companion cropping with a row of basil planted between adjacent tomato rows significantly lowered B. tabaci infestation in tomatoes by 68.7%. Better tomato yields were also recorded in treatments where the two treatments were used in combination. Higher yield (13.75 t/ha) was obtained from tomatoes grown under agronet cover with a basil row planted in between adjacent rows of the tomato crop compared to 5.9 t/ha in the control. Non-marketable yield was also lowered to5.9 t/ha compared to 9.8 t/ha in the control following the use of the two treatments in combination. The results of this study demonstrate the potential viability of using companion cropping and agronet covers in integrated management of B. tabaci and improvement of tomato yield. Full article

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153 KiB

Open AccessEditorial

Special Issue: Nitrogen Transport and Assimilation in Plants

by Bertrand Hirel and Anne Krapp

Agronomy 2016, 6(3), 41; https://doi.org/10.3390/agronomy6030041 - 29 Aug 2016

Cited by 1 | Viewed by 4134

Abstract

The doubling of the world’s agricultural production for the past four decades has been associated with a seven-fold increase in nitrogen (N) fertilization [1] which has caused major detrimental impacts onthediversityandfunctioningofthenon-agriculturalbacterial,animalandplantecosystems,notably through the process of freshwater and marine ecosystem eutrophication [2].[...] Full article

(This article belongs to the Special Issue Nitrogen Transport and Assimilation in Plants)

230 KiB

Open AccessArticle

Impact of Climate Change on Cultivar Choice: Adaptation Strategies of Farmers and Advisors in German Cereal Production

by Janna Macholdt and Bernd Honermeier

Agronomy 2016, 6(3), 40; https://doi.org/10.3390/agronomy6030040 - 22 Jul 2016

Cited by 24 | Viewed by 7889

Abstract

The objective of this study is to understand which requirements for cereal cultivars—with regard to climate change adaptation—are in demand by farmers and advisors, and to clarify whether there are any differences in their assessments. A comparative survey was used to collect data from 410 farmers and 114 advisors in Germany. The majority of both farmers and advisors reported perceivable effects of climatic change on plant production. The increase in droughts and hot spells, the increased incidence of torrential rain, and mild winters were mentioned as the main effects of climate change. For climate change adaptation, the farmers and advisors mostly relied on a locally-adapted cultivar selection. It is estimated that eco-stability, grain yield, resistance to lodging and drought tolerance are important cultivar properties. In the study, farmers and advisors equally pointed out the need for additional cultivar evaluation according to eco-stability. Finally, only minor differences regarding farmers’ and advisors’ assessments were found within the study. The outcome of this research points to the need of implementing farmers’ demands in cultivar recommendations. For example, an impartial assessment of cultivars’ eco-stability could help support the choice of cultivars and reduce the growing risks in cereal production with regard to climate change. Full article

3490 KiB

Open AccessArticle

Influence of Formulation on the Cuticular Penetration and on Spray Deposit Properties of Manganese and Zinc Foliar Fertilizers

by Alvin Alexander and Mauricio Hunsche

Agronomy 2016, 6(3), 39; https://doi.org/10.3390/agronomy6030039 - 30 Jun 2016

Cited by 18 | Viewed by 7457

Abstract

Foliar fertilization, or the application of nutrient solutions to the foliage of plants, has become a very important tool as a supplement to traditional soil fertilization. So far, knowledge about the real mechanisms of foliar nutrient uptake is still limited. In this study different manganese (Mn) and zinc (Zn) carriers differing in their solubility and chemical characteristics (chelated or non-chelated, with or without the presence of a surfactant-penetrant) were compared with regard to their penetration characteristics through enzymatically-isolated cuticles. The experiments were explicitly conducted under high humidity conditions in order not to penalize compounds with a higher deliquescent point. The results show that Mn penetrates more rapidly through the cuticle than Zn ions for unknown reasons. The addition of a surfactant-penetrant enhances the penetration rate in the case of Mn ions. This trend is much less pronounced for zinc ions. Formulations based on insoluble carriers, such as carbonate or oxide, only poorly penetrate through the cuticle. In order to rapidly control micronutrient deficiency problems, only fully water soluble micronutrient carriers should be used. Full article

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Agronomy, Volume 6, Issue 3 (September 2016) – 5 articles

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