Impact of Various Organic Fertilizers on the Growth, Yield, and Soil Environment of Peanuts Subjected to Continuous Cropping Obstacles

Abstract

To clarify the improvement effect of organic fertilizer application on peanut continuous cropping obstacles, a field plot experiment was conducted in a plot that had been continuously cropped with peanut for 5 years. Equal amounts of nitrogen were applied to the plot using charcoal-based fertilizer (T2), pig manure compost (T3), and chicken manure compost (T4), while chemical fertilizer (T1) and no fertilizer (CK) were used as controls. The study investigated peanut agronomic traits, yield and its contributing factors, soil physical and chemical properties, and peanut leaf diseases. The results showed that all three types of organic fertilizers could significantly promote peanut growth, with the T3 performing the best. The main stem height, length of the first lateral branch, and number of branches per plant in the T3 were 31.45%, 21.28%, and 26.32% higher than those in the CK, respectively. There was no significant difference between the T2 and T4 s in terms of main stem height and number of branches per plant compared to the T3. In terms of yield and its contributing factors, the performance of organic fertilizers was significantly better than that of the T1 and CK s. Among them, the T3 had the highest yield, which was 36.81% and 22.07% higher than that of the CK and T1 s, respectively. There was no significant difference between the T4 and the T3. The T2 and T4 s had the highest hundred-pod weight, while the T3 and T4 s had the lowest number of pods per kilogram. There was no significant difference in hundred-kernel weight among the three types of organic fertilizers. In terms of soil physical and chemical properties, the application of organic fertilizers significantly increased soil pH, porosity, field water holding capacity, and decreased soil bulk density compared to chemical fertilizer and no-fertilizer s. There was no significant difference in these indicators among the organic fertilizer s. In terms of soil nutrient content, all fertilization s significantly increased the content of total nitrogen, alkaline nitrogen, available phosphorus, and available potassium in the soil. Among them, the organic fertilizer treatments were significantly better than the chemical fertilizer in terms of total nitrogen and available phosphorus content. Additionally, organic fertilizer s significantly increased the soil organic carbon content, with the T2 having the highest organic carbon content, which was 20.56% higher than that of the CK. In terms of soil phenolic acid content, organic fertilizer s significantly reduced the content of vanillic acid and coumarin in the soil, with the lowest coumarin content observed in the T3 and T4 s. In terms of peanut leaf diseases, the disease index of peanut leaf spot and brown spot were significantly lower in the organic fertilizer s than in the no-fertilizer and chemical fertilizer s, but there was no significant difference between the different organic fertilizer s. After the comprehensive evaluation of the affiliation function method, it can be found that T4 can alleviate the continuous cropping obstacle to the greatest extent. The conclusion drawn from this study is that biochar-based fertilizer, pig manure compost, and chicken manure compost can all promote growth, increase yield, improve soil environmental quality, and provide certain disease prevention and control effects for peanut plants under continuous cropping obstacles. It is recommended to choose organic fertilizer for application in areas where peanut continuous cropping is more serious in a timely and site-specific manner.