Effect Of Different Combination Of Water And Fertilizer On The Performance And Quality Of Alfalfa

Greenhouse pot experiment were conducted at the Experimental Base of Institute of Animal Scineces of CAAS,Langfang,Hebei Province.The effects of water and fertilizer treatment on the production performance,nutrient composition,root system and soil fertility of alfalfa by completely random design at the sandy soil.There are four fertilization gradients were selected such as 0 kg/hm²,125 kg/hm²,187.5 kg/hm²,250 kg hm²(recorded as F₀,F₁,F_2,F₃)of each cut,and three water gradients were used such as deficit?W₁50%⁵5%of soil holding capacity?,moderate water?W₂,65%⁷0%?,high water?W₃ 80%⁸5%?.The main results showed as follows:1.Total hay yield increased with the increase of irrigation amount.Water and fertilizer content can increase the yield of alfalfa.The best combination of water and fertilizer is F₃W₃,250 kg/hm²fertilizer and 80%⁸5%of soil holding capacity.Under the condition of higher soil fertility,the appropriate increase of irrigation quantity can improve the annual yield and plant height of alfalfa,and the yield of alfalfa was greatly improved under W₃ treatment.2.Fertilization can increase the root surface area of alfalfa,and the lower irrigation treatment is beneficial to the increase of root weight of alfalfa.The development of alfalfa roots can be promoted under low water treatment.3.Under the effect of water and fertilizer content of N,P and K of alfalfa has a significant effect.The contents of N,P and K of alfalfa increased with the increase of fertilization amount.The total yield of alfalfa was positively correlated with the P content of alfalfa.The content of CP and EE of alfalfa increased with the increase of fertilizer application rate,while the content of ADF and NDF were decreased.Compared with several indexes,the increase of fertilizer and high water treatment could be improving the quality of alfalfa.4.Under the effect of water and fertilizer treatment,compared with the soil before and after the first crop of alfalfa,the content of total nitrogen,total phosphorus,ammonium nitrogen and nitrate in soil decreased after the third cut.Under the F₂ and F₃ treatments,the total potassium content of the soil was higher than that of the pre-sowing soil.The pH of the soil grown by alfalfa increased with the soil before sowing.5.In summary,we suggested that cultivation of alfalfa in the semiarid sandy soil has to increase fertilizing amount and follow as high water treatment during the first and the second cutting of grown stage.