灌溉方式与施磷对紫花苜蓿产量、水磷利用及土壤磷组分的影响

针对紫花苜蓿生产中灌溉水分和水磷利用率不理想的问题,采用双因素裂区设计,设置不同磷施用量(0、50、100、150 kg/hm^(2),P_(0)、P_(1)、P_(2)、P_(3))和灌溉方式(常规畦灌、干湿交替灌溉、浅埋灌溉,W_(1)、W_(2)、W_(3)),探究灌溉方式与施磷互作对紫花苜蓿产量、水磷利用及土壤磷组分的影响,为紫花苜蓿优质高产栽培与水磷协同管理提供理论依据。结果表明,相同灌溉方式下,随施磷量增加,紫花苜蓿总磷积累量、干草产量、水分利用效率、磷肥利用效率(PUE)、土壤全磷、难利用性磷、中等程度利用性磷、极易利用性磷及土壤转化酶均呈先增加后降低的趋势,以P_(2)存在较大值;土壤磷代谢酶(ACP、LCP)活性、有机磷、易利用性磷及磷活化系数(PAC)呈持续增加趋势。相同施磷水平下,W_(2)、W_(3)处理的上述指标均高于W_(1)处理。整体而言,W_(2)P_(2)处理具有最高的产量,其他处理3年平均较其降低1.21%~20.42%,PUE、PAC分别减少0.09~13.03百分点、1.09~9.16百分点。综上,施磷量为100 kg/hm^(2)结合干湿交替灌溉时,可促进土壤磷转化,提高紫花苜蓿水、磷利用效率及生产性能。

Growth Responses of Wheat Cultivars to Rock Phosphate in Hydroponics

Screening cultivars to grow under conditions of low phosphorus (P) availability and utilize P efficiently from compounds of low solubility in soils may be beneficial to overcome poor plant growth in P-deficient soils. The growth behavior and P utilization efficiency of seven wheat cultivars grown in hydroponics were studied, using rock phosphate as P source. The wheat cultivars grown for 30 days were significantly different in biomass accumulation, P uptake and P utilization efficiency. The dry matter production of all the cultivars was significantly correlated with P uptake, which in turn correlated to the drop in the root medium pH. The ranking of wheat cultivars on the basis of dry matter yield, P uptake and P utilization efficiency was Zamindar 80 > Yecora > C 271 > WL 711 > Barani 83 > PARI 73 > Rohtas. The cultivar Zamindar 80 appeared to possess the best growth potential in P-deficient soils.