【摘要】 研究了在施肥与不施肥处理情况下,半湿润偏旱区春谷子不同生育期氮、磷、钾养分的吸收特点。结果表明:在供试土壤条件下,施肥可明显提高春谷子产量、干物质累积量、体内氮、磷、钾含量及其累积量;施肥或不施肥,春谷子地上部干物质的累积量随生育期呈典型"S型"曲线增长,其中抽穗灌浆期为累积高峰期,占总累积量的50%左右;植株氮含量随生育期呈曲线下降趋势,整个生育期植株含磷量呈"W型"变化,植株含钾量呈单峰曲线变化,峰值出现在拔节期;植株氮、磷、钾累积吸收量随生育期的延长和施肥水平的提高而增加,但各生育期相对累积吸收比例,施肥与否差异不大;苗期氮、磷、钾的吸收量约占总吸收量的1%~3%,拔节期约占总吸收量的30%、20%、37%,是钾素吸收的高峰期,孕穗期约占22%、21%、34%,抽穗灌浆期约占43%、53%、23%,是氮、磷吸收的高峰期,籽粒形成期约占3%~5%;不论施肥与否,地上部氮、磷、钾累积吸收量与干物质累积量之间均呈极显著正相关,而与植株氮、钾含量之间呈极显著负相关。更多还原

【Abstract】 The field experiment were conducted in semi-humid region to investigation the characteristics of N, P and K uptake of spring millet at different growth stages. Two fertilization treatments were set up (N 150 kg/m2、P2O5 75 kg/m2、K2O 90 kg/hm2 and cK) with four replicates. The results showed that application of N, P, K fertilizers remarkably increased grain yields, weights of dry matters, and N, P and K contents and accumulates. Whatever fertilization levels, the above-ground dry matter accumulate increased with the growth stages and showed a typical S-shape. There were a peaks of dry matter accumulation occurred at filling stages and account for about 50% of total accumulation. The content of N in plants showed a downward tendency with growth stages; the content of P law of spring millet appeared "W" model; the content of K in plants showed a unimodal curve during the growing stage, and reached the maximum at jointing stages. Under all experimental condition, N, P and K accumulation increased with both growth stages and fertilization rates, and the proportion of nutrient accumulate at different growth stages was almost same. On average, N, P, K uptake accounted for 1%-3% of the total uptake at seedling stages. During jointing period, the absorbed rates accounted for 30%, 20%, 37%, respectively, which the K uptake was highest at this stages comparing with the others. The absorbed rates accounted for 22%, 21%, 34% at pregnant ear stage, for 43%、53%、23% at heading and filling stages which the N, P uptake was highest at this stages comparing with the others, for 3%~5% at ripening stages. The uptake rates of N, P, K by plants were significantly positive correlated with the accumulated rates of dry matters, but were significantly negative correlated with the contents of N, K in plants either high fertility or low fertility.更多还原