Abstract: In order to explore the best fertilization combination of nitrogen,phosphorus,potassium and molybdenum fertilizers in the arid area of Ningxia,the relationship between seed yield and light energy radiation of Astragalus adsurgens was revealed. Using orthogonal experimental design,the effects of N,P,K and Mo ratios on light energy radiation,seed yield components and seed yield of Astragalus adsurgens population were investigated,and seed yield and light energy radiation were analyzed by structural equations and comprehensively evaluated using principal component analysis. The results showed that the effects of N,P,K and Mo ratios on light energy radiation,seed yield components and seed yield of Astragalus adsurgens populations were significant (P<0.05),with the T₈ (N₃P₂K₁Mo₃) fertilization combination having the greatest radiation use efficiency,thousand grain weight and actual seed yield,amounting to 1.39 g·MJ^-1,1.56 g and 336.55 kg·hm^-2,respectively. The structural equations showed that leaf area index had a direct negative effect on actual seed yield of Astragalus adsurgens (P<0.05),and transmittance had a highly significant direct negative effect on actual seed yield (P<0.001),which indicated that seed yield could be improved by decreasing transmittance and leaf area index in actual seed production of Astragalus adsurgens;and the through-trail analysis indicated that the improvement of seed yield of Astragalus adsurgens should be based on the increase of the number of florets/inflorescences and number of inflorescences of a single plant. Inflorescence number and number of inflorescences per plant increased. The comprehensive evaluation concluded that 180 kg·hm^-2 of N fertilizer,90 kg·hm^-2 of P fertilizer,75 kg·hm^-2 of K fertilizer,and 0.15% of Mo (T₈) were the optimal ratios for high seed yield of Astragalus adsurgens,which could be used as a reference basis of fertilizer application for Astragalus adsurgens seed production.

Key words: Astragalus adsurgens, Fertilization, Radiation use efficiency, Seed yield

摘要： 为探究在宁夏干旱区沙打旺(Astragalus adsurgens)氮、磷、钾和钼肥的最佳施肥组合，揭示沙打旺种子产量与光能辐射之间的关系，本试验采用正交试验设计，研究了氮、磷、钾和钼肥配比对沙打旺群体光能辐射、种子产量构成因素和种子产量的影响，同时对种子产量与光能辐射通过结构方程进行分析并利用主成分分析进行综合评价。结果表明，氮、磷、钾和钼肥配比对沙打旺群体光能辐射、种子产量构成因素和种子产量有显著影响(P<0.05)，其中T₈(N₃P₂K₁Mo₃)施肥组合的辐射利用效率、千粒重和实际种子产量均最大，分别达1.39 g·MJ^-1，1.56 g和336.55 kg·hm^-2；结构方程表明叶面积指数对沙打旺实际种子产量有直接负效应(P<0.05)，透光率对实际种子产量有极显著直接负效应(P<0.001)，表明在沙打旺实际种子生产中可通过减小透光率和叶面积指数提高种子产量；通径分析表明沙打旺种子产量的提高应以增加小花数/花序和单株花序数为主。综合评价得出180 kg·hm^-2尿素+90 kg·hm^-2磷酸二胺+75 kg·hm^-2硫酸钾+0.15%钼氨酸是沙打旺种子产量高产的最佳配比，可作为沙打旺种子生产施肥的参考依据。

关键词: 沙打旺, 施肥, 辐射利用效率, 种子产量