| Water resources are the key factors restricting agricultural production and ecological environment in northwest China,and in order to explore a water-saving irrigation system suitable for the high-efficiency production of drip irrigation maize in the arid zone of central Ningxia,it is of great significance to the sustainable high-yield and high-efficiency planting of spring maize in Ningxia.Therefore,It was conducted to investigate the effects of two drip irrigation quotas(M1:3300m3·hm-2,M2:3750m3·hm-2)and four drip irrigation systems on spatio-temporal distribution of soil water and nitrogen,growth characteristics of corn root system,yield and water and nitrogen use efficiency.The results are as follows:1.Compared with M1,soil water content of 0-80cm during R1 and R1+20d has been improved by M2,the soil water content in 60-80cm soil layer during R1 was increased significantly.Compared with M2,nitrate nitrogen content in 0-80 cm soil layer at R1 has been improved by M1,while increased nitrate nitrogen content in 60-80 cm soil layer at R1 was increased significantly.Under different irrigation systems,there was no significant difference in soil water content between different from V6 to V12.The treatments with higher proportion of irrigation between V12 and R1(D1 and D2)significantly increased soil water content at Rland R1+20d,but there was no significant difference in soil water content among treatments after R1+20d.Dl and D2 significantly increased the content of nitrate nitrogen in 0-80cm soil at R1.Under the combined action of the two factors,M2D1 and M2D2 had higher soil water content and nitrate nitrogen content at R1.Soil nitrate nitrogen in M2D4 was significantly lower than that in other treatments.2.The root dry weight,length,area and volume of different treatments increased from V12 to R1+20d.Compared with M1,M2 significantly improves root growth characteristics in 0-80 cm soil layer,and has a significant impact on the root growth characteristics in 0-40 cm soil layer.Compared with the treatments with lower irrigation allocation before V6(D1 and D2),root growth characteristics has been increased by D3 and D4.The compensation effect of root growth characteristics is more obvious with the increase from V12 to R1 irrigation distribution,of which D1 is the most significant,followed by D2.With the increase of irrigation allocation ratio from large trumpet to R1,the compensation effect of root index was more obvious.The root weight and root activity of D1 increased most significantly,followed by D2.On the R1+20d,D1 and D4 were the best,and the root activity of D4 was significantly lower than that of D1.Under the combined action of the two factors,M2D3 and M2D4 were higher root growth characteristics at V12,The root area and volume of the M2D1 and M2D4 were significantly higher than those of other treatments at R1.M2D1 was the highest root length,M2D4 was the highest root dry weight,and M2D1 and M1D1 had the highest root activity after R1+40d.3.Compared with M1,the accumulation of dry matter at R1 and R6 has been significantly increased by M2.D3 and D4 significantly promoted dry matter accumulation from V6 to V12,while D1 and D4 had higher dry matter and nitrogen accumulation at R1,The accumulation of dry substances D1 and D2 in maturity increased by 8.33%and 7.36%respectively over D4.The corn leaf area and the high-efficiency leaf area were the highest in D1 40 days after flowering,followed by D2,D4 is the lowest.The higher leaf area in the late growth stage of D1 and D2 treatments significantly increased the dry matter accumulation after anthesis.and D4 significantly increased the amount of dry matter transport after flowering.Under the combined effect of two factors,the accumulation of total dry matter in the mature period increased significantly by 9.22%and 7.55%compared with M1D3,M2D1 significantly increased the accumulation of dried material after flowering,and M2D4 significandy increased the amount of dry matter transport after flowering.4.M2 mature grain nitrogen accumulation and total nitrogen accumulation,as well as nitrogen transport indicators are higher than M1.Compared with D3 the total nitrogen accumulation of each organ during the D1 and D4 maturation periods increased significantly by 23.33%and 25.52%,while the accumulation of nitrogen in grains D1 and D2 increased significantly by 22.05%and 17.59%respectively compared to D4.Under the combined effect of two factors,the total nitrogen accumulation M1D1 and M2D1 in maturity significantly increased by 27.59%and 21.65%compared to M2D3,M1D1 and M2D1 significantly increased the accumulation of post-flower nitrogen,while M2D3 and M2D4 significantly increased the amount of nitrogen transfer after flowering,and the contribution rate of nitrogen transfer after flowering and nitrogen transfer after flowering.5.Compared with M1,spring corn grain yield has been significantly increased.by M2,but the difference in water efficiency between M1 and M2 was not significant.D1 and D2 significantly increased grain yield and water utilization efficiency,reduced corn bald tip length,and increased spike length and spike grain count.Under the combination of two factors,corn yield was the highest at M2D1,at 16702.52 kg.hm-2,and the number of spike M2D1 was up to 590.66 grains.In conclusion,when the drip irrigation quota is 3750 m3·hm-2,the distribution ratios of 15%,55%,and 30%respectively,from VE to V6,V12 to R1,R1+20d to R6,which was suitable for local drip irrigation corn water-saving irrigation system. |
PDF Full Text Request