Effects of Sowing Method and Nitrogen Fertilizing Rate on Production Performance of Timothy Genotypes in Alpine and Humid Regions of Gansu
To determine the optimal nitrogen fertilizing rate,sowing method,and the suitable timo-thy genotype,a split-plot design was employed to study the effects of four nitrogen fertilizing rates(A1:0 kg/hm2,A2:90 kg/hm2,A3:180 kg/hm2 and A4:360 kg/hm2)and three sowing methods(B1:drill,B2:broadcast and B3:dibble)on the production performance of four timothy genotypes(C1:New timothy line,C2:'Chuanxi',C3:'Minshan'and C4:'Clover 1')in an alpine and humid area of Gan-su province.Single factor analysis showed that treatment A4 had the highest average production per-formance among the four nitrogen fertilizing rates,while B3 had the best average production perform-ance among the three sowing methods,C1 had the highest average production performance among the four genotypes.The interaction between two factors showed that,treatment A4C3 had the highest av-erage production performance among the interactions between nitrogen fertilizing rates and genotypes,while the treatment B3C1 had the best average production performance among the interactions be-tween sowing method and genotypes,the treatment A4B3 had the highest average production per-formance between the interactions between nitrogen fertilizing rates and sowing methods.The interac-tion of the three factors showed that C1 had the best average production performance under treatment A2B3,while C2 and C4 had the best average production performance under treatment A4B3,C3 had the highest average production performance under treatment A4B2.In conclusion,for the new timothy line,a nitrogen fertilizing rate of 90 kg/hm2 and dibble sowing are the best sowing method.For'Chuanxi'and'Clover 1',the best nitrogen fertilizing rate is 360 kg/hm2,and dibble sowing is the preferred sowing method.On the other hand,for'Minshan',the best nitrogen fertilizing rate is also 360 kg/hm2,but,the broadcast sowing,is the recommended sowing method.