Effect Of Sowing Date On Nutrient And Water Utilization Of Spring Maize

The regulation of sowing date is one of the important technical measures to increase the yield of maize.In order to clarify the influence of sowing date on spring maize plants,soil nutrients and moisture,and to provide theoretical basis for the selection of suitable sowing date and the efficient utilization of natural resources in eastern Hebei.In this study,the high-yielding and resistant spring maize cultivars JNK728 and MC812 selected by the research group in the early stage were used as experimental materials,and a total of 4 sowing dates were set on May 1(B1),May 10(B2),May 20(B3)and May 30(B4).The main results are as follows:1.The sowing date had a significant effect on the contents of alkali-hydrolyzed nitrogen,available phosphorus and available potassium of spring maize in different growth stages and soil layers.In seedling stage,soil nutrient content was lower in early sowing treatment and higher in late sowing treatment.Maturation is the opposite.2.Sowing date had a significant effect on nutrient accumulation and translocation of maize.The nitrogen accumulation of the two cultivars was the highest in B4 treatment,the phosphorus was the highest in B3 treatment,and the potassium was the highest in B2 sowing time.The transport of N and p elements and their contribution rates to grains were higher in the next two sowing dates.The K element transport and contribution rate of JNK728 and organ to grains were the highest under treatment of B1,and the potassium transport and contribution rate of MC812 were the highest under treatment of the latter two sowing dates.Under different sowing date treatments,the nutrient harvest index and production efficiency of the two maize varieties were higher under B4 treatment,while the nutrient absorption of 100 kg maize grains was lower under B4 treatment.3.Sowing date had a significant effect on the water consumption and water use efficiency of the two maize varieties,but the difference between the two varieties was not significant.Since the first two sowing dates were hit by drought in the stage ofhuge bellbottom period and tassel period,a supplementary irrigation was carried out.Therefore,with the delay of sowing date,the total water consumption showed a trend of decreasing first and then increasing.B4 was used to treat the maximum.The trend of WUE was consistent with that of water consumption.Under the natural precipitation condition,the WUE in B4 sowing period was the highest.4.The delay of sowing date had a certain influence on the accumulation and transportation of dry matter in the later period of maize growth,and the variation of maize varieties was slightly different.B4 was the largest dry matter accumulation in JNK728,while MC812 was the lowest in B3.Under different treatments,B4 sowing time was the lowest for dry matter transport and contribution rate to seeds.5.Sowing date had a significant effect on agronomic traits of the two cultivars,but the difference between cultivars was not significant.With the delay of sowing date,the plant height and spike height of the two varieties of maize increased,while the stem diameter decreased.Spike length,spike thickness,shaft thickness and bald tip length all decreased first and then increased with the delay of sowing date,while row grain number decreased gradually.6.Under the treatment of different sowing dates,the yields of JNK728 and MC812 were the highest treated by B4.The number of grains per spike decreased with the delay of sowing date,and the 1000-grain weight was consistent with the change of yield,decreasing first and then increasing,and the 1000-grain weight under the treatment of B4 was the largest.