不同施肥水平对山药生长发育的影响及基于产量反应的养分用量推荐

采用田间小区试验方法,研究了不同氮磷钾施用水平对山药生长发育特性及产量的影响。结果表明:从播种至收获,山药地上部生物量(鲜重和干重)均随生育期的延长呈先增加后降低的趋势,120 d时达最大值;地上部生长速率和干物质累积速率的最快阶段均出现在90～120 d;地下部生物量呈现出随生育期延长而逐渐增加的趋势,其生长速率和干物质累积速率的最快阶段亦均出现在90～120 d。当山药缺施氮、磷、钾肥时,产量降低幅度分别可以达到21. 19%～41. 17%、20. 01%～26. 07%和4. 97%～33. 86%。说明在目前适种山药的土壤肥力水平下,氮、磷、钾中任一种元素供应不足均不利于山药的生长发育和干物质累积,其中以氮的影响最大,钾次之,磷最小。同时,山药产量随氮磷钾施用量的提高呈现二次抛物线或线性加平台趋势变化。根据施肥量和产量的拟合方程得出目标产量下的最佳施肥量为N 301. 1 kg/hm~2,P_2O5165. 9 kg/hm~2和K_2O290. 3 kg/hm~2。

Effects of different fertilization levels on growth characteristics of yam and nutrient recommendation based on yield response

A field experiment was conducted to investigate the effect of different levels of nitrogen (N),phosphorus (P) and potassium (K) on growth characteristics and yield of yam.The results showed that the fresh weight and dry weight of the above ground part increased and then decreased obviously during the growth period from sowing until harvest,and the highest value was observed at 120 d after sowing.The fastest rate of growth and dry matter accumulation of above ground part both appeared at 90~120 d.While the fresh weight and dry weight of under ground part gradually increased in the whole growth period,and the fastest rate of growth and dry matter accumulation also appeared in 90~120 d.The deficiency of N,P or K decreased the yam yield by 21.19%~41.17%,20.01%~26.07% and 4.97%~33.86%,respectively.In conclusion,the lack of N,P or K could affect the dry matter accumulation and growth of yam.Nitrogen is the major limited factor for yam growth,followed by K,and P is the least.Respectively,the yam yield showed two variation tendencies:parabolic or linear plus platform with the increasing of N,P and K application rate.According to the correlation equation of fertilization rate and yield,the optimum fertilization rate of yam is N 301.1 kg/hm2,P2O5 165.9 kg/hm2,and K2O 290.3 kg/hm2.