2.2. Preparation of cattle manure compost
Cattle manure was obtained from the nearby Hongyi Organic Farm, in Jiang Jiazhuang Village of Pingyi County. It was shaped into cuboids with width 1.5 m, height 0.5 m, with moisture content of 70%. The compost was covered with plastic film, stirred and mixed every 20 days. After 90 days, the resulting cattle manure compost (CMC) was applied into the fields before sowing. The manure compost contained organic matter 40.61%, total nitrogen (N) 2.11%, total phosphorus (P2O5) 0.52%, total potassium (K2O) 1.78% and had moisture content of 68.9%.