滴灌条件下水肥耦合对番茄光合、产量和干物质分配的影响

ttttt目的ttttt研究干热河谷区旱季膜下滴灌灌溉下不同水肥处理对甜脆玉米生殖生长期光合、形态、产量的影响。ttttttttttttt方法ttttt以‘正甜68’为试验材料，设计裂区区组大田种植试验，其中水分处理共3个梯度：低(W1)55%~90%田间持水量；中(W2)70%~90%田间持水量；高(W3)每5 d浇1次，每次2 h(约2.270 5 m³)。施氮肥处理共4个梯度：F1：75 kg/hm²；F2：75 kg/hm²+叶面微肥；F3：150 kg/hm²；F4：150 kg/hm²+叶面微肥。水分和施肥交叉结合，共12个处理。
分析不同水肥组合下玉米的净光合速率(P_n)、胞间CO₂浓度(C_i)、气孔导度(G_s)、蒸腾速率(T_r)、水分利用效率(WUE)、形态指标、产量等指标。tttttttttttttttttt结果ttttt不同水肥处理在生殖生长期以前光合及生长量都没有显著差异(P>0.05)，在进入生殖生长后期则出现显著差异(P>0.05)，光合速率最高值[35.06 μmol/(m²·s)]出现在高水分处理组。在水分利用效率方面，灌溉水利用率最高值[4.203 2 kg/m³(鲜重)]出现在低水分处理组，而最低值[2.292 8 kg/m³(鲜重)]出现在高水分处理组；在产量方面各处理组差异不显著(P>0.05)。tttttttttttttttttt结论ttttt研究区高温、干旱、少雨，水分因素是主要的影响因子，玉米的灌溉水利用率随着灌溉量的减少而升高，水分处理对玉米生理效应显著，肥料的处理属于次要因素，对玉米生理有一定的影响。tttt

Stomatal conductance and photosynthesis

tttttPurposetttttJinsha River dry-hot valleys (DHV) of Yuanmou in Yunnan Province Southwest of China have high temperature and drought all the year round. A plot experiment was designed in this area to research the water-fertilizer coupling of sweet corn (Zea mays L.).ttttttttttttttttttMethodtttttThere were three irrigation levels [low (W1), 55%-90% field capacity (Fc); medium (W2), 70%-90% Fc; and high (W3), watering 2 hours every 5 days (approximate 2.270 5 m³)], four nitrogen fertilizer levels [F1 (75 kg/hm²); F2 (75 kg/hm²+foliar fertilizer); F3 (150 kg/hm²); F4 (150 kg/hm²+foliar fertilizer)]. The twelve irrigation and fertilization treatments were T1(W1×F1), T2(W1×F2), T3(W1×F3), T4(W1×F4), T5(W2×F1), T6(W2×F2), T7(W2×F3), T8(W2×F4), T9(W3×F1), T10(W3×F2), T11(W3×F3), T12(W3×F4), respectively. Some parameters of maize were determined. They were net photosynthetic (P_n), intercellular CO₂ concentration (C_i), atomatal conductance (G_s), transpiration rate (T_r), water use efficiency (WUE), morphological parameters and yield.ttttttttttttttttttResultstttttThe photosynthesis and morphological parameters were no significant differences (P>0.05) in the early reproductive stage of sweet corn in different watering and fertilizing treatments, but there were significant differences (P>0.05) in the later reproductive stage, in which stage the high water treatment groups showed a significant advantage in photosynthesis.
TheP_n was higher in W3 treatment group, compared with other groups, the maximum value was 35.06 μmol/(m²·s). For water use efficiency, the irrigation water use effciency (IWUE) was higher in the W1 groups [the maximum value was 4.203 2 kg/m³(FW)], while lower in the W3 groups [the minimum value was 2.292 8 kg/m³(FW)]. There was no significant difference (P>0.05) in the yield.ttttttttttttttttttConclusiontttttThe study area was characterized by high temperature, drought with little rainfall, so water was the main limiting factor. The IWUE increased with the decrease of irrigation quantity. The water treatment significantly effected on the physiological of sweet corn, while the fertilizer treatment was the secondary factor, as it had a little effect on the physiology of sweet corn.tttt