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Making more efficient use of nitrogen in crop rotations of horticultural crops - HH3506SFV

Description
Large amounts of N are applied to agricultural land to support profitable and competitive farm enterprises. However, abilities to effectively manage this N over the long-term are lacking, with the result that agriculture is a key contributor of greenhouse gases arising from denitrification, and nitrate leaching, which results in pollution of drinking water and freshwater habitats. The use of computer models offers great potential to improve the prediction and management of N fluxes in soil. However, such models are limited in 1. The accuracy with which they predict mineralisation, particularly in the winter 2. The number of crops which they represent.In a range of agricultural systems incorporating both conventional and organic practices, serious seasonal and site discrepencies occur between computer simulated and actual rates of net N mineralisation. There is a need to consider the impact of soil variability in the models, and to develop a mechanistic understanding of soil microbial mineralisation-immobilisation processes, in order to improve their reliability. These are key objectives of the proposed study Research is being carried out on a European Scale through the EU-Rotate_N project to develop a new decision support systems for estimation of nitrogen requirements for field vegetable crops for whole crop rotations. The current project will work in synergy with EU_Rotate_N to improve the prediction of the contribution of N from crop residues and the cycling of nitrogen between crops in a rotation. However it is never enough to produce a research model, it needs together with the results of the scientific research upon which it is based to be demonstrated to the industry. Part of this project will be dedicated to technology transfer both to and from the industry. This will be achieved by the formation of targeted alliances with advisors and specialists in several organisations including, Vegetable Consultants Association (VCA), ADAS, and FACTS networks. The results of research need to be delivered using real farm examples so a number of demonstration sites will be set up to provide a focus for discussions with growers on more effective use of N over crop rotations. These sites will be regularly monitored to assess the changes in soil mineral N, crop N and residue N on key dates during crop rotations. These alliances will lead to the setting up of regular briefing meetings at least once a year to discuss relevant issues relating to N supply and N turnover between crops. At each of these meetings representatives from Defra will be invited. The specific aims of this project are to: 1. To integrate existing knowledge on the cycling of N in soils particularly from field vegetable crop residues into a form suitable for inclusion into new models for management of N in field vegetable crop rotations. 2. Determine the effect of climatic variables on the the structure of the soil microbial biomass contributing to crop residue decomposition, and its implications for N mineralisation processes 3. To include new knowledge into working versions of the EU-Rotate-N model.4. To provide a basis for 2 way technology transfer between the research community and providers of advice to the horticultural Industry to improve N cycling between crop rotations of field vegetable crops.This project would address the Defra HH35 Sustainable Crop Nutrition Roame objective of "Forecasting the fate and impact of added nutrients in soil". The results would add considerable value to the research being carried out in the EU-Rotate_N project (Funded by Framework V ending December 2006) which aims to develop a Europe-wide decision support system to improve the efficiency of nitrogen use by field vegetable crops. This system will be of use to Policy makers, farmers and consultants.
Objective
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
Time-Scale and Cost
From: 2004

To: 2008

Cost: £896,695
Contractor / Funded Organisations
Warwick - HRI
Keywords
Brassicas              
Farming              
Horticulture              
Natural Resource Use              
Nutrition              
Sustainable Farming and Food              
Vegetables