Effects of liquid manure replacing chemical N fertilizer in rice-rapeseed rotation on crop yield and fertilizer use efficiency
[Objectives]Reasonable application of liquid manure is a vital way to reduce the utilization of chemical fertilizers and realize the recycle of organic nutrients.This study explored the effects of different proportions of liquid manure in total fertilizer inputs on crop yield,fertilizer use efficiency,and annual nutrient budget.[Methods]Field experiment was conducted at Dajin Town,Wuxue City,Hubei Province during the period of 2021-2023.The five fertilization treatments included no fertilizer control(CK),farmers'practice(FP),optimized fertilization(OPT),and replacing 15％,and 30％of chemical fertilizer N in OPT treatment with liquid manure(BS15,BS30).The cropping system was rice-rapeseed rotation.At harvest,the yield and nutrient uptake of crops were analyzed,and the fertilizer use efficiency and annual nutrient budget were evaluated.[Results]Compared with FP treatment,OPT and BS15 treatment significantly increased rapeseed yield by 15.8％-25.0％,agronomic use efficiency of fertilizer by 25.0％-31.3％,partial productivity of fertilizer by 21.1％-23.7％,and K2O uptake by 12.4％-15.7％,and increased the above items in rice by 16.1％-19.3％,42.1％-44.7％,13.5％-16.1％,16.3％-18.9％;BS30 treatment did not cause significant difference.Compared with FP,OPT and BS15,BS30 treatment significantly decreased crop N uptake and P2O5 uptake of rapeseed by 10.0％-11.5％,15.0％-18.0％,and those of rice by 19.4％-25.5％,16.5％-21.0％.The annual apparent budget for N was surplus in 64-132 kg/hm2 in all the fertilizer treatments,and that of K2O was deficit in 137-255 kg/hm2,and that of P2O5 was in deficit of 69 kg/hm2 and 44 kg/hm2 in FP and OPT,while surplus 37 kg/hm2 in BS30.The BS15 treatment had the annual P2O5 budget closest to apparent balance(P2O5,-14 kg/hm2).[Conclusions]Replacing 15％of chemical fertilizer N with liquid manure can improve crop yield,fertilizer use efficiency and nutrient uptake of rapeseed and rice,while maintaining P2O5 apparent balance throughout the rotation system.It is recommended to use liquid manure to replace 15％of chemical fertilizer N in rice-rapeseed rotation.
rice-rapeseed rotationliquid manureyieldfertilizer use efficiencynutrients apparent balance
万方数据
维普
