滴灌水氮运筹对南疆春小麦根系生长及产量的影响

以南疆地区春小麦新春6号为供试材料,采用土柱栽培法,通过滴灌开展水、氮两因素控制性试验,滴施纯氮量设N₀(不施氮肥)、N₁(69 kg·hm^-2)、N₂(172.5 kg·hm^-2)和N₃(276 kg·hm^-2)4个水平,滴灌水量设W₁(2 250 m³·hm^-2)、W₂(3 000 m³·hm^-2)、W₃(3 750 m³·hm^-2)和W₄(4 500 m³·hm^-2)4个水平,共16个水氮组合处理。结果表明:扬花期是滴灌春小麦根系生长的高峰期,有64.52%～76.90%的根系干质量和76.39%～82.47%的根长分布在0～40 cm土层中。适当增施水氮能有效促进根系...

Effects of drip irrigation and nitrogen application on root growth and yield of spring wheat in Southern Xinjiang

The spring wheat cultivar Xinchun 6 in the Southern Xinjiang was selected as the test material, and two\|factor (water and nitrogen) controlling experiments were conducted using soil\|column cultivation method. Four levels of nitrogen supply, including N₀ (no N fertilizer), N₁ (69 kg·hm^-2), N₂ (172.5 kg·hm^-2), and N₃ (276 kg·hm^-2), and four levels of water supply, including W₁ (2 250 m³·hm^-2),W₂ (3 000 m³·hm^-2), W₃ (3 750 m³·hm^-2), and W₄(4 500 m³·hm^-2), were used for fertigation and drip irrigation, respectively. Thus, 16 water\|nitrogen\|combination treatments were implemented. The results showed that flowering stage was the peak period of root growth of spring wheat drip irrigation and 64.52%~76.90% of the root dry mass and 76.39%~82.47% of the root length were distributed in 0~40 cm soil layer. Increasing the water supply and nitrogen properly effectively promoted root growth and improved yield of spring wheat. The root dry mass, root dry mass density, root length, root length density, root diameter, and root surface area of N₃W₃, N₂W₃, and N₃W₂ treatments at flowering stage were higher, which were 123.0~148.3 mg, 97.07~117.03 g·m^-3, 14 405.8~16 490.8 mm, 1.14~1.30 cm·cm^-3, 0.3267~0.3365 mm, and 14 245~17 624 mm², respectively. The yield under N₃W₃, N₂W₃, and N₃W₂ treatments also reached a higher level of 8 695.7~9 966.1 kg·hm^-2. Although the root indexes under the N₃W₄ treatment were higher, yet they declined too fast during wax ripening period, which indicated that excessive water and nitrogen supply was unfavorable for delaying root senescence. Water and nitrogen had significant interaction effects on root growth and yield, and water had greater effect than nitrogen did. Through analysis, the suitable supply ranges of water and nitrogen for this region was 3 750~4 500 m³·hm^-2 and 172.5~276 kg·hm^-2, respectively. When nitrogen application and water drip were 259.4 kg·hm^-2 and 3 793.4 m³·hm^-2, respectively, the yield could reach the maximum value of 9 142.9 kg·hm^-2.