Abstract:

In order to combine the wastewater of pig farm as a source of nutrient with cropping and realize the goal of environment protection, results of this study could provide the scientific basis for efficient wheat production that supports large-scale pig farming. In this paper, by field experiment, different combinations of large-scale pig farm wastewater (30, 60, 90, 120 m3/hm2) in winter and nitrogen fertilizer (0, 30, 60, 90 kg/hm2) at heading stage were designed to test the influences of wheat dry matter accumulation and yield formation. The main research results were as follows: at elongation stage, the wheat dry matter accumulated with the amount of waste water increasing. At heading stage, dry matter accumulation achieved the highest under the combination of 90 m3/hm2 wastewater with 30 kg/hm2 nitrogen fertilizer. At maturity stage, dry matter accumulation achieved the highest under the combination of 30 m3/hm2 wastewater with 90 kg/hm2 nitrogen fertilizer and 120 m3/hm2 wastewater with 30 kg/hm2 nitrogen fertilizer. The wheat yields were higher than others under these combinations: 30 m3/hm2 wastewater and 60 m3/hm2 nitrogen fertilizer, 90 m3/hm2 wastewater and 30 m3/hm2 or 60 m3/hm2 nitrogen fertilizer, 120 m3/hm2 wastewater and 30 m3/hm2 nitrogen fertilizer. Considering the high farm wastewater bearing capacity and the target of fertilizer reduction, spreading 90 m3/hm2 to 120 m3/hm2 wastewater in winter and 30 m3/hm2 nitrogen fertilizer at heading stage was the optimal combination. In conclusion, the pig farm wastewater has efficient fertilizer function. When it was combined with reasonable amount of fertilizer, the yield can exceed conventional fertilizer production and the amounts of nitrogen fertilizer can also be cut down.