Evaluation Of Nutrient Utilization Efficiency And Soil Fertility Quality In Different Planting Patterns Of Double-Cropping Region In Southern Part Of North China Plain

In the southern part of the North China Plain,a double cropping pattern of corn-wheat with chemical fertilizer input is the common planting pattern in most of this area,which caused some problems in farmland soil such as nutrient imbalance and bad structure of soil,so the promotion of soil quality and the development of sustainable agriculture are restricted to some extent.In this study,different planting patterns including corn-wheat,soybean-wheat,peanut-wheat and sweet potato-wheat were implemented to analyze the nutrient content and structural properties of the0-100 cm soil layer and the utilization efficiency of different crops,as well as the evaluation of soil fertility quality.The conclusions are as follows:1.There were some differences of organic matter,nitrogen,phosphorus and potassium content among these four planting patterns.For the soil organic matter,its content in 0-30 cm and 30-60 cm soil layer in soybean-wheat pattern was higher than that in corn-wheat,peanut-wheat or sweet potato-wheat patterns,which was the lowest in 0-15 cm layer in corn-wheat pattern.For nitrogen element,the total nitrogen content in 15-30 cm and 30-60 cm soil layer in soybean-wheat pattern was significantly higher than that in the other three patterns(P<0.05),and the available nitrogen content in 0-30 cm soil layer in corn-wheat pattern was only at 57.0% in soybean-wheat pattern,and it in60-100 cm soil layer in the sweet potato-wheat pattern was the highest among these treatments.And the ammonium nitrogen content 0-30 cm soil layer and the nitrate nitrogen content in the 30-60 cm and 60-100 cm soil layers were the highest in the sweet potato-wheat pattern.For the phosphorus element,the total phosphorus content in the 0-30 cm and 30-60 cm soil layers was the highest in the soybean-wheat pattern,but which was the lowest in the corn-wheat pattern.The available phosphorus content in 0-15 cm soil layer was the highest in peanut-wheat pattern,which higher than that in corn-wheat,soybean-wheat,sweet potato-wheat by 18.94%,26.78% and 26.78%respectively,while the available phosphorus content in 15-30 cm and 30-60 cm soil layers was the highest in sweet potato-wheat pattern and that the lowest in corn-wheat pattern.To the potassium element,the total potassium content in 0-30 cm soil layer was the highest in sweet potato-wheat pattern,and the content of total potassium and available potassium were significantly lower than that in the other three patterns(P<0.05).2.The total annual amount of nitrogen,phosphorus and potassium in the soil were allunbalance in these four planting patterns.The total amount of nitrogen was deficient in 0-100 cm soil,and the lack in soybean-wheat pattern was the lowest about half of the lack amount in the corn-wheat pattern.The shortage of total phosphorus amount was at 5.4% in corn-wheat pattern,while the abundance of it in soybean-wheat,peanut-wheat and sweet potato-wheat patterns reached by 11.2%,1.6% and 1.5% respectively.The total amount of potassium were all in the surplus state in these four patterns,which abundance amount was the highest in sweet potato-wheat pattern and was the least in soybean-wheat pattern.3.The utilization efficiency of nitrogen,phosphorus and potassium for crops were different in four different cropping patterns,which in the sweet potato-wheat pattern was the highest,that was respectively 3.28,3.22 and 2.39 times than that in the soybean-wheat pattern.The nitrogen harvest index of sweet potato-wheat pattern was the smallest,which was at 79.60% in soybean-wheat pattern.And the harvest index of phosphorus in the corn-wheat pattern was the biggest,which was higher than that in soybean-wheat,peanut-wheat and sweet potato-wheat pattern by 4.12%,20.71%and 14.48% respectively.The potassium harvest index was the largest in the soybean-wheat pattern,which was more than that in corn-wheat,peanut-wheat and sweet potato-wheat patterns about 0.08,0.16,and 0.09 respectively.4.Through the annual profit and loss balance analysis of the soil-crop systems on nitrogen,phosphorus and potassium,the nitrogen was all showed deficient in these four planting patterns.Compared to other treatments,the nitrogen shortage of the soybean-wheat system was the least,but that of the peanut-wheat pattern was the most.In addition,the soybean-wheat pattern showed the most phosphate surplus,while the corn-wheat system showed the least shortage.However,there were all abundance of potassium in these four planting patterns,and that was the highest in the sweet potato-wheat pattern,while the abundance amount of potassium in corn-wheat,soybean-wheat and peanut-wheat patterns were higher than the sweet potato-wheat pattern by71.49%,52.69% and 72.56 % respectively.5.Compared with the corresponding wheat planting patterns,fallow pattern in winter was conducive to the accumulation of nitrogen and phosphorus in soil,with corn-fallow pattern was the most obvious one,whose total amount of nitrogen and phosphorus increased by 22.12% and33.27% respectively in 0-100 cm soil layer.The total amount potassium in 0-100 cm soil layer in the fallow area was decreased in varying degrees except that in the soybean-fallow pattern.6.Compared to the common corn-wheat planting pattern,the quality of soil was improved in soybean-wheat,peanut-wheat and sweet potato-wheat patterns.And the soil fertility quality indexes were 0.401 in corn-wheat planting pattern,0.526 in soybean-wheat,0.480 in peanut-wheat and0.490 in sweet potato-wheat pattern.