Ploughing down harvest residues of preceding crops for the purpose of soybean yield improvement

Soybean yield depends on the choice of cultivar, soil fertility, cultivation practices, and weather conditions in different years. Ploughing down crop residues increases the content of soil organic matter, and thereby positively affects soil fertility. The use of crop residues as an energy source has been promoted in recent years. It would be wrong to refer to this as a renewable energy source as the removal of crop residues from agricultural fields reduces and ultimately damages soil fertility, which in turn leads to reduced yield and a crop residue decrease in the future. Due to the reduced application of manure and organic fertilisers, it is necessary to return crop residues to the soil to preserve soil structure and prevent soil fertility decline. The effect of ploughing down crop residues of preceding crops on soybean yield has been the focus of studies for eleven years. Ploughing down maize crop residues resulted in the soybean yield increase by about 11.69%, i.e. the annual yield increase ranged from 2.89% to 15.94%.