Abstract:
Objective The paper aimed to provide technical support for rational and efficient fertilization of newly constructed greenhouse soil.
Method The rice husk biochar and green manure rapes were used as the test materials. Three treatments were designed: biochar free and green fertilizer (0 + 22500 kg hm−2, GM), biochar green fertilizer combination (22500 + 22500 kg hm−2, BC + GM), and biochar free and green fertilizer free (0 + 0 kg hm−2, CK). A maize cultivation experiment was conducted in a small plot to study the effects of rape overturning and biochar application on soil properties.
Results The research results showed that the BC + GM treatment had the highest soil aggregate structure R0.25 value, the lowest soil bulk density and the highest field water capacity during the entire process of overturning fertilization. The soil organic matter, dissolved organic carbon, total nitrogen, ammonium nitrogen, available phosphorus, available potassium content, and CEC were all the highest. On the 28th day, they were 4.86%, 1.45 g cm−3, 24.08%, 17.82 g kg−1, 115.33 mg kg−1, 0.91 g kg−1, 1.31 mg kg−1, 45.16 mg kg−1, 428.93 mg kg−1 and 18.09 cmol (+) kg−1, respectively. They were all significantly higher than those in the CK treatment (P < 0.05). The GM treatment had the second best effect, but the soil nitrate nitrogen content and pH value of this treatment were the highest and the lowest, with values of 232.56 mg kg−1 and 7.87 on the 28th day, respectively, which were significantly higher than those of the CK treatment (P < 0.05). The soil urease activity, alkaline phosphatase activity, and microbial biomass carbon and nitrogen content were the highest in the BC + GM treatment, with values of 0.690 mg (g d)−1, 0.2628 mg × 10−1 (g d)−1, 151.81 mg kg−1 and 5.71 mg kg−1 on the 28th day, followed by GM treatment, while CK treatment had the lowest effect, and there was a significant difference between CK treatment and BC + GM treatment (P < 0.05). In addition, the yield and dry matter weight of maize kernels treated with BC + GM were also the highest.
Conclusion Overall, BC + GM treatment (22,500 + 22,500 kg hm−2) has the best effect on improving soil properties and can be prioritized for soil fertility improvement in newly constructed greenhouses in the local area.