Effects Of Fertilization And Density On Seeds Yield Of Lespedeza Davurica

Lespedeza davurica is an excellent grass species for forage and grassland improvement.The demand for seeds in ecological construction and forage production is increasing,but the seed yield of Lespedeza davurica is low and the quality of seeds is poor.Therefore,in this three-year field study,we tested the effects of N(0,75,125,175 kg/hm2)P(50,100 kg/hm2)K(75,150 kg/hm2)fertilizer and plant density(6 and 12 plants/m2)on seed yield and seed yield constructing factors of Lespedeza davurica ‘Jin Nong 1'.This test is a split plot experiment with fertilization as the main area and planting density as the sub-area.A yield prediction model is established after obtaining key factors affecting seed yield.This last test provides a theoretical basis for increasing seed yield in Lespedeza davurica.The results show:(1)With the increase of fertilizer application,the overall trend of seed yield increased first and then decreased(P<0.01).With the increase of planting density,the trend of seed yield decreased(P<0.01),and the seed yield was the highest when the planting density was 6 plants/m2.Fertilization and planting density significantly affected seed yield and seed yield(P<0.01).Under the two planting densities,with the increase of fertilization amount,the seed yield of Lespedeza davurica increased first and then decreased.The planting density was 6 plants/m2,the fertilization amount was N125P50K75,the seed yield per plant was 15.67g/plant,and the seed yield was 940.20kg/hm2.(2)Among the seed yield components of Lespedeza davurica,seed yield(Y)and secondary branch number(X2),plant height(X3),raceme number/branches(X4),florets/raceme(X5),pods number/raceme(X6)showed a very significant positive correlation(P<0.01).The key factors affecting Lespedeza davurica seed yield are: raceme number/branches(X4)> florets number/inflorescence(X5)> pods number/raceme(X6)> secondary branch number(X2)> plant height(X3).(3)The optimal regression equation for wheat seed yield is obtained by stepwise regression analysis: Y =-407.8-79.1X1 + 7.6X2 + 4.1X3 + 24.0X4 + 49.0X5 + 35.2X6-271.2X7(R2=0.564,P<0.001).