Soil fertility, managing fertilisers

Yield is not the only indicator of farm productivity. Inputs used to deliver those yields should also be considered, and can be in the form of materials, as discussed below, but they may also be in different forms. For example, one way to manage soil fertility and pest problems on organic farms is to employ a different rotation from that on conventional farms where synthetic fertilisers and pesticides can perform those tasks. Because of the difference in rotation, which may also mean a larger diversity of crops, the whole farm needs to be considered when determining productivity and profitability. 

High biological activity within the soil promotes metabolism between soil and plants and is an essential part of sustainable plant production and fertiliser management. The role of soil organisms is central to soil processes and fertility since they render available the elements in plant residues and organic debris entering the soil (Alfoldi ef al. 2002). 

Colvan, S.R., Syers, J.K. and O Donnell, A.G. (2001) Effect of long-term fertiliser use on acid and alkaline phosphomonoesterase and phosphodiesterase activities in managed grassland. Biology and Fertility of Soils 34, 258-263. 

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