Effects of Pig Manure Composts on Lettuces Quality and Nitrogen/Phosphorus Utilization Efficiency in Huang-Huai Plain

Abstract

The prevailing problems in countryside, such as excessive use of chemical fertilizer and large amounts of livestock manure, need to be addressed urgently. In order to optimize the amount of applied organic fertilizer, the experiment was carried out in the planting-breeding combined circular agricultural area of Huang-Huai plain and the effects of pig manure fertilizer amounts on lettuces yields, quality and nitrate/phosphorus utilization efficiency were investigated. It was found that the replacement of chemical fertilizer with organic fertilizer had no significant effects on the N and P content of lettuces when treated with the same amounts of fertilizer. However, it could improve its yield, quality, and nitrogen/phosphorus utilization efficiency. When the ratio of organic fertilizer replacement was 25%∼75%, the nitrate and nitrite content of lettuces were reduced by 19.41% and 73.33% compared with the chemical fertilizer treatment. The nitrogen and phosphorus utilization efficiency in the 75% organic fertilizer replacement were highest, which were 30.4%/44.9% higher than that of chemical fertilizer respectively. Above all, the 75% organic fertilizer with 25% fertilizer group had the best effect on the yield of lettuces, improving the quality and utilization efficiency of nitrogen and phosphorus fertilizer. The results could provide an important scientific basis for determination of regional vegetable planting fertilizer and reduce the non-point source pollution risk.