| 【Objective】In view of the prevailing problems such as excessive use of chemical fertilizer, decline
in quality of agricultural products and the massive storage of livestock and poultry waste in rural areas, the experiment of
fertilizer replaced by organic pig manure was carried out.【Method】In order to optimize the application amount of organic
fertilizer and the replacement ratio of chemical fertilizer by organic fertilizer, the experiment was carried out in typical
planting-breeding combined area of Huanghuai region by using the field plot trial method, and the effects of application amount and the replacement ratio of pig manure fertilizer on lettuces production, quality and nitrate/phosphorus utilization
rates were investigated. The basic fertilization amount (M) was N 200.0 kg /hm2, P2O5 96.8 kg/hm2, and the fertilizer amount(M
reduced by 50%, M, and M increased by 100%) and organic fertilizer replacement ratios (0% M, 25% M, 50% M, 75% M, and
100% M, based on nitrogen and phosphorus) were set according to test requirements.【Result】When the fertilizer amount
was less than M, the yield of lettuces and the utilization rate of nitrogen and phosphorus increased with the increase of fertilizer
application rate under the condition of single organic fertilizer application. When continuing to increase the amount of fertilizer
application, the yield increased insignificantly, and the quality and nitrogen and phosphorus utilization rates decreased slightly.
When fertilization amount was the same, replacing certain amount of chemical fertilizer with organic fertilizer had no significant
effect on the nitrogen and phosphorus contents of lettuces, but it could improve its yield, quality and nitrogen and phosphorus
utilization rates. When the replacement ratio of organic fertilizer was 25%-75%, the nitrate and nitrite contents of lettuces were
reduced by 19.4% and 73.3% (P＜ 0.05) compared with those of the chemical fertilizer control. The highest utilization rates
of nitrogen and phosphorus was obtained with an organic fertilizer replacement ratio of 75%, which were 30.4% and 44.9%
higher than those of chemical fertilizer control.【Conclusion】The 75% organic fertilizer with 25% chemical fertilizer group
has the best effect on the yield of lettuces, and can improve the quality and utilization rate of nitrogen and phosphorus fertilizer
effectively. The results of this study provide an important scientific basis for the determination of fertilizer reduction for regional
vegetable planting and reduce risk of non-point source pollution. |
