春季有限灌水对海河平原冬小麦根系生长及籽粒产量的影响OA北大核心CSTPCD

Clarifying the effect of spring limited irrigation on the root development and grain yield of winter wheat in Haihe Plain is of great significance to reduce irrigation and improve water use efficiency.This study used Shimai 22 as the test material,irrigation treatments were traditional irrigation twice at jointing and anthesis stage(W2),no irrigation(W0),and single irrigation(W1)with four irrigation-time treatments(3L,4L,5L,and 6L)based on the number of leaves unfolded in spring.The results showed that compared with W2,W0 and W1 yield decreased by 54.6％and 24.4％re-spectively,the irrigation yield was highest at 4L in W1,and the effect of yield composition reduction was not significant.Limited irrigation reduced the total root weight density and root length density of winter wheat.During the anthesis peri-od,the total root weight density of W1 decreased significantly by 17.2％,while the total root weight density and root length density of W0 decreased significantly by 47.5％and 35.1％,respectively.And under W1 condition,4L has the highest total root weight density and root length density.The vertical distribution of roots showed that reducing the fre-quency of irrigation increased the distribution of roots in the soil layer below 40 cm,however,with the postponement of ir-rigation time,the root distribution of W1 deep soil decreased and root vigor increased.Among them,during the anthesis period,4L was significantly higher than 6L by 28.8％,14.2％,and 36.5％in the 120-160 cm,160-200 cm,and 200-240 cm soil layers,respectively.Correlation and path analysis showed that total root weight density and root length density at joint-anthesis period had a positive effect on yield.The direct contribution of total root length density in 3L and 4L irrigation was the largest.Generally speaking,the root mass of 4L treatment was higher at jointing-anthesis period,the deep root distribution and root activity of 40-240 cm were increased,resulting in higher spike number and kernel number,which was beneficial to alleviate the decrease of winter wheat yield at limited irrigation,it can be used as an ef-fective way of limited irrigation for winter wheat in Haihe Plain.