Effects Of Different Water And Fertilizer Treatments On Growth And Soil Fertility Of Green Manure And Main Crops In Yunnan/Shandong Province

Dryland agricultural regions are the main producing areas of grain crops and cash crops in China.The unreasonable and excessive use of chemical fertilizer leads to the agricultural ecological degradation and the decreasing of soil qualityand nutrient use efficiency in upland.Based on the principle of annual nutrient equal weight,we collected the Vicia villosa Roth var.and corn rotation in red upland of Yunnan Province and the Orychophragmus violaceus(L.)O.E.Schuz and peanut rotation in brown upland of Shandong Province,to study the influence of irrigation and fertilization on the growth of green manure and its green manure on the yield,soil fertility of the main crop and nutrient utilization after tumbling.The experiment of Vetch and corn rotation and the Orychophragmus violaceus and peanut rotation were arranged in the fall of 2017.We setted 10 different irrigation and fertilization treatments including winter idle land treatment(CF),control without irrigation and fertilization in the green manure season(CK),application of nitrogen fertilizer in the green manure season(N),application of same annual nitrogen fertilizaer with reduction in main crop season(EN);application of phosphorus fertilizer in the green manure season(P),application of same annual phosphorus fertilizer with reduction in main crop season(EP),application of nitrogen and phosphorus fertilizer in the green manure season(NP),application of same annual nitrogen and phosphorus fertilizer with reduction in main crop season(ENP),green manure growing season amended with irrigation but without fertilization treatment(CKW),green manure growing season amended with nitrogen and phosphorus fertilizer and irrigation treatment(NPW).The main findings are as follows:In the experiment of the Vetch and corn rotation in Yunnan red soil,the results showed that both irrigation and fertilization significantly promoted the growth of Vetch.In the green manure season,regardless of fertilization,the biomass,root activity,N and P nutrients accumulation of Vetch were significantly increased under irrigation treatment.Compared with the corresponding treatment without irrigation,the Vetch biomass,root activity,N and P nutrients accumulation of NPW and CKW were consistently increased by 34.58%and 56.10%,26.49%and 37.92%,43.47%and 146.89%,103.84%and 113.94%,respectively.The amount of nutrients returning from the residual Vetch were125.32～274.49 kg/hm2 and accounted for 26.95%～59.03%of the total nutrients of the corn season.Compared with CF,poughing green manure with different fertilization and irrigation treatments promoted corn yield and nutrient accumulation,and increased soil nutrients among which the effect of NPW treatment was most obvious.Under same annual nutrient condition,15.67%of nitrogen and or 50.00%of phosphorus fertilization in the corn season transferred forward to the green manure growing season,which significantly increased the biomass of green manure nutrient return,the yield of corn(8.39%～31.19%)and nutrients accumulation(7.31%-29.20%).In the experiment of the Orychophragmus violacens and peanut rotation in brown soil of Shandong,the results showed that both irrigation and fertilization significantly promoted the growth of Orychophragmus violaceus.In the green manure season,regardless of fertilization,the biomass,N,P and K contents of Orychophragmus violaceus significantly increased under irrigation treatment.Compared with the corresponding treatments without irrigation,the Orychophragmus violaceus biomass,root activity,and contents of N,P and K of NPW and CKW were consistently increased by 66.47%and 63.97%,76.95%and 32.36%,88.31%and 9.80%,21.71%and 15.56%,respectively.The amount of nutrients returning from the residual Orychophragmus violaceus was 91.04 kg/hm2-260.23 kg/hm2,accounting for 27.59%～78.86%of the total nutrients of the corn season.Compared with CF,the green manure growing with different fertilization and irrigation treatments promoted peanut yield and nutrient accumulation,and increased soil nutrients among which the effect of EN was most obvious.Under same annual nutrient condition,35.00%of nitrogen and/or 42.86%of phosphorus fertilization in the peanut season transferred forward to the green manure growing season,which significantly increased the amount of residue incorporation of green manure and the corn yield(22.82%-41.18%).In summary,under the conditions of appropriate irrigation and fertilization,the biomass of green manure was increased significantly and its returning consistently increased the yield and nutrient accumulation of later main crop.Part of the main crop season fertilizer moved forward to the green manure season,which promoted the increase of the main crop yield,and also promoted the soil fertility.Our research can provide data to support the application of green manure and fertilizer reduction to field managements in China.