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.