灌水次数和施磷量对冬小麦养分积累量和产量的影响

为给利用灌水和施肥措施调控小麦生长提供科学依据,在大田环境条件下,分别于2007-2008年（丰水年）在保定市、2008-2009年（平水年）在藁城市用当地冬小麦推广品种（河农822、冀5265）进行二因素裂区试验,研究了灌水次数（保证底墒的基础上设全生育期灌0、1、2和3次水3个灌水水平,分别用W0、W1、W2和W3表示）和施磷量（设0、75和150 kg·hm^-2 3个施磷水平,分别用P0、P1和P2表示）对小麦养分积累量和产量的影响。结果表明,灌水次数和施磷量对小麦植株的氮、磷、钾积累都有促进作用,但促进效果受降水年型的影响。丰水年灌水次数对氮、磷、钾积累量的影响较小,平水年灌水次数对氮、磷积累量的影响显著,氮、磷积累量在生育中后期都随灌水次数增加而提高,钾素积累量各生育时期受灌水影响不一致。丰水年施磷对氮素积累量影响不明显,磷素积累量随施磷量增加而增加,钾素积累量生育前中期以P0和P2较高,后期以P2较高;平水年,氮素和钾素积累量均随施磷量增加而增加,而磷素积累量受施磷量影响较小。适当灌溉和施磷可提高小麦养分生产效率、氮素和磷素收获指数,对钾素收获指数的影响较小。2年中灌水处理（W1、W2、W3）的籽粒产量均显著高于不灌水处理W0,但2007-2008年W1产量最高,2008-2009年则表现为W3>W2>W1。2年中P1和P2的籽粒产量均显著高于P0,但2007-2008年P1产量最高,2008-2009年P2产量最高,显示出磷素与水分的互补作用,即“水少磷多”或“水多磷少”都可以实现高产。根据研究结果,在河北平原常年降水（小麦全生育期100 mm左右）条件下全生育期灌溉2次,施P₂O₅ 150 kg·hm^-2;丰水年（200 mm左右）全生育期灌溉1次,施P₂O₅ 75 kg·hm^-2,可以取得较理想的产量。

Effect of Irrigation Times and Phosphorus Application Rate on Nutrient Accumulation and Grain Yield of Winter Wheat

In order provide scientific bases for the regulation of wheat growth and development with irrigation and fertilization measures, field experiments were carried out during 2007-2008 (rich rainfall year) in Baoding, and 2008-2009 (moderate rainfall year) in Gaocheng with local commecial winter wheat cultivar Henong 822 and Ji 5265, respectively. The experiments during the two years were designed as split plot arrangement, with irrigation time as main plots (including 0, 1, 2 and 3 times, expressed as W0, W1, W2 and W3 respectively), and phosphorus application rate as split plots (including 0, 75 and 150 kg·hm^-2 P₂O₅, expressed as P0, P1 and P2 respectively). The results showed that, both irrigation and P application increased the accumulation of N, P and K by wheat plant, but the increaments were affected by rainfall. The effects of irrigation times on nutrient accumulation was less significant in rich rainfall year than that in moderate rainfall year, when the accumulation amount of N and P increased with the increase of irrigation times. The effects of P application rate on the accumulation amounts of N and P during mid late growing period increased with the increase of irrigation times, but the effect of irrigation on the accumulation amount of K was different at various growing stages. In rich rainfall year, the accumulation amount of N was less affected by P application, but that of P increased with the increase of P application rate, and that of K was higher in the treatments P0 and P2 during mid early growing period. In moderate rainfall year, however, the accumulation amounts of N and K increased with the increase of P application, but that of P was less affected by P application. The production efficiencies of all the three nutrients, i.e., N, P and K, and the harvest indices of N and P of wheat increased in the treatments with appropriate irrigation and P fertilization, but the harvest index of K was less affected by irrigation and P fertilization. The grain yields of W1, W2 and W3 with irrigation were all significantly higher than that of W0 without irrigation during the two growing years. The grain yield of W1 was the highest during 2007-2008, but the grain yields increased with the increase of irrigation times during 2008-2009. The grain yields of P1 and P2 were all significantly higher than that of P0 during the two years. The grain yield of P1 was the highest during 2007-2008, but that of P2 was the highest during 2008-2009, showing the compensation effect between phosphorus and water supply, i.e., high grain yield can be achieved by different pathway either "less water and more phosphorus" or "more water and less phosphorus". According to the results, it is recommended that two irrigations during the growing period be needed, with 150 kg·hm^-2 P₂O₅ applied for satisfactory grain yield of winter wheat under moderate rainfall (about 100 mm during winter wheat growing period) in Hebei Plain of China. In rich rainfall year, however, one irrigation be sufficient, with 75 kg·hm^-2 P₂O₅.