Effects of compost on yields of winter wheat and barley, sugar beet, onion and swede in the fourth and fifth years of a rotation

Abstract

Background
This is the final report of a project investigating the use of green waste derived compost in agriculture, which received funding in part from the HGCA during 2005 and 2006. The project itself ran for five years: Initially a three year project was funded by GrantScape through the Landfill Communities Fund with support through the Applied Research Forum by the British Potato Council (BPC), the Home-Grown Cereals Authority (HGCA) and the Horticultural Development Council (HDC). The project was then extended by a further two years.

The project was managed by Phil Wallace of Enviros Consulting Ltd with Iain Turner and Will Baldwin of Envirofield carrying out the field trials management. Additional research was conducted by Dr Martin Wood of Earthcare Environmental Ltd. Soil nutrient balances and economics were carried out by Anna Becvar, an independent soil scientist.

Key benefits found

During the five year period of trials the following key benefits were quantified:

Soil physical condition

• Increased soil organic matter
• Increased soil water holding capacity
• Improved water infiltration giving less run off and risk of soil erosion
• Improved soil structure and workability

Soil chemistry and soil life

• Stabilised soil pH
• Increased biological population and microbial activity
• Increased soil available potassium and other nutrients
• Optimum use of applied fertiliser nitrogen when applied with compost

From all five years of trial results, these benefits led to an average yield increase of 7% where compost had been used regularly.