Effects Of Maize-peanut Intercropping On Soil Fertility Characteristics

Maize-peanut intercropping can improve the iron nutrition of peanut, promote the activity of peanut nodule nitrogen fixation, and improve the uptake ability of iron nutrition and nitrogen nutrition. It also has obvious interspecific rhizosphere effect. However, the impact of maize-peanut intercropping on the top layer of soil still need further study. Therefore, the maize-peanut intercropping at 2:4 mode as the research object in this experiment, we studied the root soil nutrient, crumb structure, the characteristics of soil enzyme activity and soil microorganism, and the utilization of plant nutrient under the application of phosphorus and no-phosphorus, to explain the effects of maize-peanut intercropping on soil fertility characteristics, which provided the theoretical basis to explain the high efficient and high yield of maize-peanut intercropping. The study was made in 2014 at Henan University of Science and Technology Farm. The results showed as follows:Compared with the single cropping, maize-peanut intercropping significantly increased the content of the soil water stable aggregates and the soil respiration rate. After application of phosphate fertilizer, the content of the intercropping system soil aggregates was further increased by the 7.3%, and the soil respiration rate of intercropping system increased by the 7.7%-11.4%, the differences were significant. The result shows that the intercropping system can improve the soil physical structure.Maize-peanut intercropping improved the content of the soil organic matter, nitrogen, phosphorus and iron. Compared with the single cropped maize, they were respectively increased by 8.5%-9.8%, 23.3%-25.9%, 24.4%-31.2% and 4%-13.8%. Compared with the single cropped peanut, they were respectively increased by 19.1%-27.9%, 11.1%-13.3%, 10.1%-46.4% and 10.9%-21.1%. The differences have reached the significant level. Maize-peanut intercropping also significantly reduced the soil p H value. This shows the intercropping system can effectively improve the nutritional status of the root-zone soil of maize and peanut, it also can promote the activation of soil nutrients. Phosphorous application can further increase the content of available nutrients in the soil.Maize-peanut intercropping can significantly increase the activity of urease, alkaline phosphatase, sucrase and catalase in soil. Compared with the single cropped maize, they were respectively increased by 2.1%-14.0%, 1.1%-11.8%, 13.0%-54.8% and 2.2%-7.3%. Compared with the single cropped peanut, they were respectively increased by 3.2%-31.4%, 24.2%-41.4%, 4.3%-22.9% and 2.9%-9.7%. Maize-peanut intercropping also obviously changed the biological quantity and community structure of the soil bacteria, fungi, actinomycetes, nitrogen-fixing bacteria and symbiotic nitrogen-fixing bacteria. This shows the intercropping system can effectively improve soil enzyme activity and promote the formation of microbial diversity. Phosphorous application can further increase the soil enzyme activity.The utilization of nitrogen, phosphorus and iron of the maize-peanut intercropping were between single cropped maize and single cropped peanuts. The nitrogen harvest index and the iron harvest index of the intercropping system increased by 4.87% and 9.56% respectively, and the phosphorus harvest index of the intercropping system significantly increased by 11.48% after application of phosphate fertilizer.Maize-peanut intercropping obviously showed the yield advantage of intercropping, the LER values were greater than 1. The intercropping system can significantly improve the yield of maize by 76.6%-125.9%. After application of phosphate fertilizer, the yield advantage of the intercropping system significantly increased by 16.2%-81.6%.