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Improving the sustainability of crop nutrition in horticultural soil - HH3508SFV

Large amounts of fertilizers are applied to agricultural and horticultural land to support profitable and competitive farm enterprises. However, methods to effectively manage fertilizer inputs over the long-term are lacking, with the result that farming is a major contributor of greenhouse gases arising from denitrification, and nitrate and phosphate leaching, which results in pollution of drinking water and freshwater habitats. There is a need to make more effective use of inherent soil resources so that fertiliser inputs can be reduced, and losses minimised. Precision farming, in which fertilizer and other inputs are tailored to the precise requirements of a field or area within a field offers the potential to reduce the environmental impact of horticulture while increasing production efficiency and reducing costs. Effective utilization of soil resources for crop nutrition requires identification of the key contributors to nutrient supply in soil, and factors controlling their spatial and temporal variability. N and P supply to crops is a function of the delivery of these nutrients in a plant-available form to the plant. In the absence of mineral fertiliser addition, this requires the mineralization of soil organic matter by soil microbes, and for many plants, delivery of nutrients by symbiotic arbuscular mycorrhizal fungi (AMF) to the plant root. Soil organic matter is composed of a variety of pools with different labilities and functional roles, and it is unclear which of these pools contribute to mineralization processes. AMF are a major component of the soil microbiota in low input systems, and have the potential to contribute to nutrient uptake by many horticultural crops. Many practices typical of conventional horticultural production are deleterious to AMF communities.However the abundance and diversity of AMF in horticultural soils is unclear. Further it is not known how crop nutrition is affected by the diversity of AMF available. This project aims to improve understanding of the chemical and microbiological factors that control nutrient supply in horticultural soil so that inputs can be adjusted to maximise production efficiency and minimise pollution. This project has 3 inter-linked components: 1. To elucidate the relationships between labile soil organic matter (SOM) fractions, nutrient availability and management practice, using statistical tools including meta-analysis, in order to identify SOM fractions contributing to sustainable nutrient supply 2. To determine the diversity of AMF communities in horticultural soils, and the effect of AMF diversity and individual AMF species on the nutrition of a variety of horticultural crop plants 3. To investigate how within-field spatial variability and management practices influence SOM fractions contributing to soil nutrient supply and AMF diversity. The work will provide a number of outputs for use by DEFRA, growers, biotechnology companies and researchers, including;1. Qualification of new chemical and biological indicators of sustainable crop nutrition 2. Identifying management options to promote soil properties contributing to nutrient supply3. Quantifying the role of native and inoculant AMF communities to crop nutrition4. Determining the optimum characteristics of AMF inoculum required for horticulture5. Establishing the potential for using management practices to optimise SOM pools contributing to N mineralization and AMF diversity
Objective 01 Identification of new soil quality attributes for use as indicators of sustainable nutrient supply Objective 02 To develop a method suitable for characterising the structure and diversity of arbuscular mycorrhizal fungus (AMF) communities in soil, based on 18S rRNA terminal restriction fragment length polymorphism Objective 03 To establish the size and diversity of AMF communities in horticultural systems Objective 04 Determine soil factors controlling the responsiveness of crop plants to native and introduced communities of AMF Objective 05 Determine the effect of AMF diversity on horticultural crop growth and nutritionObjective 06 Characterise factors controlling the within-field diversity of AMF and indicators of N mineralization Objective 07 Determine the effect of crop management practices on the diversity of AMF and indicators of N mineralization
Project Documents
• Final Report : Improving the sustainability of crop nutrition in horticultural soil   (418k)
Time-Scale and Cost
From: 2004

To: 2008

Cost: £665,333
Contractor / Funded Organisations
Warwick - HRI
Allocated - WHRI              
Natural Resource Use              
Sustainable Farming and Food              
Fields of Study