水磷耦合对小麦耗水特性和子粒产量的影响

在低磷地力、沙质壤土条件下,选用强筋小麦品种济麦20,设置全生育期不灌水(W0),灌底墒水+拔节水+开花水,每次灌水30 mm （W1）、60 mm（W2）、90 mm （W3） 4个灌溉处理;每个灌溉处理下设置不施磷(P0)、施P2O5105 kg/hm2（P1）、210 kg/hm2（P2）3个施磷量处理,研究了水磷耦合对麦田耗水特性、产量及水分利用率的影响。结果表明,1）在同一磷素水平下,随灌水量增加,小麦总耗水量增大,降水量和土壤供水量占耗水量的比例降低。综合考虑耗水量、产量、收获指数、水分利用率等指标,最优处理为P1W2处理,其次为P1W1处理,其总耗水量分别为435.5 mm、366.0 mm,灌水量、降水量和土壤供水量占耗水量的比例分别为41.3%、39.3%、19.3%和24.6%、46.8%、28.6%;开花至成熟阶段的耗水量占小麦全生育期耗水量的36.9%～43.3%,此阶段两处理的日耗水量、耗水模系数分别为4.6 mm、3.6 mm和42.3%、39.3%。2）施用磷肥,各处理的干物质积累量增加,子粒产量表现为W2、W3W1W0,W2、W3处理之间差异不显著;与不施磷肥的处理比较,显著提高了土壤供水量占总耗水量的比例。3）收获指数和水分利用率均为W1W2W3,P2水平下W1、W2、W3处理的收获指数和水分利用率均低于P1水平。以上结果表明,在本试验条件下,施磷（P2O5）105 kg/hm2(P1)、灌水180 mm(W2)的处理获得高产和较高的水分利用率;施磷（P2O5）105 kg/hm2（P1）、灌水90 mm（W1）的处理获得较高的产量,水分利用率显著高于上述处理,耗水量则显著低于上述处理,可供生产中水资源不足的情况下参考。

Effects of irrigation and phosphorus fertilizer application on water consumption characteristics and grain yield of winter wheat

Effects of irrigation and phosphorus fertilizer application on water consumption characteristics, water use efficiency and grain yield in wheat were studied in the field experiments which were carried out on low phosphorus and sand soil with organic matter 13.6 g/kg, total nitrogen 0.85 g/kg, alkali-hydrolysable nitrogen 49.7 mg/kg, available phosphorus 6.86 mg/kg and available potassium 46.6 mg/kg in the experimental farm of Shandong Agricultural University, Taian city, Shandong province, China, using the cultivar “Jimai 20” which has strong gluten potential. Four irrigation amounts were set with no water (W0), basal + jointing + anthesis water at 30 mm (W1), 60 mm (W2), 90 mm (W3) every time, and three phosphorus fertilizer(P2O5) rates were set with 0 (P0), 105 (P1) and 210 (P2) kg/ha, respectively. Each treatment had three replicates, and the plot area was 1.5 m×6 m. The basic seedling rate was 180 plant/m2. The results indicated that under the same phosphorus rates, with increasing irrigation, water consumption amount increased, but the ratio of precipitation amount and soil water amount on water consumption amount reduced significantly. The total water consumption amount of treatment P1W2 and P1W1, which had higher yield, harvest index, water use efficiency and lower total water consumption amount than other treatments, was 435.5 and 366.0mm, respectively; irrigation amount, precipitation, and soil water consumption amount was 41.3%, 39.3% , 19.3%and 24.6%, 46.8%, 28.6% of total water consumption amount, respectively. The water consumption percentage from jointing to maturity was from 36.9% to 43.3%. The daily water consumption and the module index of them were 4.6 mm, 3.6 mm and 42.3%, 39.3%. Phosphorus improved dry matter accumulation and the turn of grain yield was W2、W3W1W0. Compared with treatment P0, the ratio of soil water consumption amount to total water consumption amount were increased. The turn of the harvest index and water use efficiency was W1W2W3, and the harvest index and water use efficiency of treatment P2 were significantly lower than treatment P1. Based on these results, it is concluded that the treatment with phosphorus application at P2O5 105 kg/ha, irrigation at 180 mm could get high grain yield and water use efficiency. And the treatment with phosphorus application at P2O5 105 kg/ha, and irrigation at 90 mm also could get high grain yield, its water use efficiency was higher than treatment W2P2, but its water consumption amount was lower than treatment W2P2, which has practical implications for regions with water resource shortage.