Effects Of Irrigation And Fertilizer Regime On Alfalfa Performance And Soil Moisture

With the rising of the grassland and animal husbandry and the implementation of the Ministry of Agriculture "Grain to forage" project,Pasture cultivation is widely spreading in China..Alfalfa as "the king of forage",is the most important forage of high quality.Our study was based on two years' alfalfa cultivation in the greenhouse,by analysing alfalfa biomass,root distribution,water consumption,soil moisture and nutrients in response to irrigation cycle and spilt application of fertilizer,quantitative assessed the effect of fertilizer and water on related indicators,and determined the optimal treatment.The main results are as follows:1)Annual aboveground biomass of alfalfa increased first and then reduced with the increase of irrigation cycle,and the highest value appeared in 4 days treatment,which was significantly higher than that of 2 and 15 days treatment(p<0.05).While,the underground biomass of alfalfa reduced firstly and then increased with the increase of irrigation cycle,the highest value appeared in 15 days treatment,The highest value of total biomass appeared in 4 days treatment,which was significantly higher than that of 2?10 and 15 days treatment(p<0.05).There was no significant difference in the effect of different fertilization treatments on alfalfa biomass.2)The appropriate irrigation cycle(4 days)can increase the soil moisture content of 0-40 cm soil layer,larger irrigation cycle(6,10,15 days)can increase soil moisture content of 40-100 cm soil layer.Water use efficiency of alfalfa increased firstly and then reduced with the increase of irrigation cycle,and the highest value appeared in 4 days treatment.Meanwhile,with the increase of irrigation cycle,the values of water consumption dropped at first and rose later.15 days treatment has the highest water consumption,significantly higher than 4,6 and 10 days(p<0.05).3)In every soil layer,the contents of available N were lower than those before planting in all fertilization treatments,and the average content of 0-100 cm soil layer decreased by 21.44 %?25.33 %? 32.10 % in one-time fertilization,two-time fertilization and four-time fertilization treatments respectively.This indicates that the output of nitrogen after the experiment is greater than the input.The results showed that the fertilization reduced the residual nitrogen in the soil,which could promote the absorption and utilization of available nitrogen and reduce the probability of leaching and environmental pollution.4)There was no significant difference in the effect of different treatments on ANF?NDF and CP of alfalfa.Alfalfa biomass,water consumption,soil nutrients and moisture and other indicators were comprehensive compared,4 days' irrigation cycle has the better performance,and the recommended fertilization is the one-time fertilization.