底墒和磷肥对旱地小麦籽粒灌浆特性及产量的影响

Effects of soil moisture before sowing and phosphate fertilizers on grain filling characteristics and yield of dryland wheat

为分析黄土高原旱地小麦灌浆过程与水分消耗的关系,及其产量对底墒和磷肥的响应情况,在山西省南部设3个播前0~100cm土壤底墒水平W1(248mm)、W2(233mm)、W3(205mm)和两个施磷量P1(75kg·hm-2)、P2(180 kg·hm-2),调查不同处理下小麦总耗水、土壤水消耗、各生育阶段耗水、产量及其构成因素、灌浆过程的变化。结果表明,随着底墒水平提高小麦返青-拔节和拔节-开花阶段耗水、生育期总耗水、土壤水消耗及其占总耗水比例、产量、穗数、千粒重显著增加,且较W3,W1和W2产量分别显著高14.89%和8.66%。随磷肥增加播种-拔节耗水显著减少,而拔节-开花耗水、产量、千粒重显著增加。底墒和磷肥互作对小麦总耗水、土壤水消耗、播种-返青阶段耗水、拔节-成熟阶段耗水、千粒重有显著影响。通过小麦灌浆方程得,快增期持续时间随底墒的增加而增加、渐增期和快增期持续时间随磷肥的增加而增加、缓增期籽粒增加量及持续时间变异系数达25%。通过小麦水(磷)肥方程得,当0~100 cm底墒为253 mm时获得高产,且同底墒下产量随磷肥增加而提高。可见,旱地小麦拔节-开花阶段耗水对底墒和磷肥敏感,灌浆过程中的快增期持续时间对底墒和磷肥响应较好,缓增期变异对籽粒粒重影响较大。

The water needed for dryland wheat growth is provided by soil moisture and rainfall.To some extent,the wheat yield is determined by soil moisture before sowing.This study aimed to analyze the relationship between the grain filling process and water consumption in the Loess Plateau(China),and investigate the response of dryland wheat yield to soil moi sture before sowing and phosphate fertilizer.A field experiment was conducted in the southern Shanxi Province of China.There were two factors in the experiment:1)soil moisture before sowing in the 0–100 cm soil layer,including three levels at W1(248 mm),W2(233 mm),and W3(205 mm);and 2)phosphorus fertilizer rates at P1(75 kg·hm-2)and P2(180 kg·hm-2).We first investigated the changes in total wheat water consumption,soil water consumption,water consumption during each growth stage,yield and yield components,and grouting process under different treatments.Collected data we re analyzed using multiple regression with a Logistic fit.The results showed that soil moisture before sowing had a significant effect on water consumption during the greening-jointing and jointing-anthesis stages.The total water consumption during the growth period,the soil water consumption,and the proportion of total water consumption,yield,spike,and thousand-grain weights were also influenced significantly by soil moisture before sowing.Compared with W3,yields of W1 and W2 significantly increased by 14.89%and 8.66%,respectively.Phosphate fertilizer has a significant effect on yield,spike,thousand-grain weight and water consumption in the wheat sowing-greening,greening-jointing,and jointing-anthesis stages.With the increase of phosphorus fertilizer,sowing-jointing water consumption decreased and jointing-anthesis water consumption,yield,and thousand-grain weight increased.The wheat grouting equation showed that the duration of the fast increase period increased with increasing soil moisture before sowing,and the duration of the increasing period and the fast-increasing period both increased with increasing phosphate fertilizer rate.The coefficient of variation of grain increased by 25%during the slow-increasing period;the wheat water(phosphorus)fertilizer equation showed that high yield can be obtained at the 0-100 cm soil moisture boundary before sowing at 253 mm.Additionally,with the same soil moisture before sowing,the yield increased with increasing phosphorus fertilizer rate.The results show that the water consumption of dryland wheat in the jointing-anthesis stage was sensitive to soil moisture before sowing and phosphate fertilizer application.The duration of the fast-increasing period in the filling process had a better response to soil moisture before sowing and phosphate fertilizer,and the variation of the slow-increasing period impacted on grain weight.