Legacy effects of soil fertility management on cereal dry matter and nitrogen grain yield of organic arable cropping systems

摘要

The yields of crops in organic farming are typically lower than in conventional farming, although this depend greatly on local climatic conditions and on crop and soil management. A long-term study over three consecutive 4-year cropping cycles at three locations in Denmark compared organic arable cropping systems varying in fertilization management (green manure crops, cover crops, livestock manure) to study the long-term effects of soil fertility management on crop yields. The analysis of the results showed that the nitrogen (N) derived from cover crops has a legacy effect on the dry matter and N grain yield of spring barley being traceable 5-8 years back in time. The net N input of crop residues and manure for the crop cycles 1-4 and 5-8 years prior to the winter wheat had a significant effect on both the dry matter and N grain yield of wheat.