Effect Of Sowing Rate On Growth Characteristics,yield And Quality Formation Of Wheat In Dry Land

In order to further explore the high-efficiency sowing method of wheat in dry land,to explore the yield and efficiency increasing ability of the furrow sowing,to clarify its optimum sowing amount,and to clarify the mechanism of the effect of sowing amount on the construction of wheat population,the optimization of population photosynthetic performance and the formation of yield and quality.The experiment was carried out in the dry land wheat experiment base of Shanxi Agricultural University in Wenxi County,Yuncheng from 2018 to 2019.The effects of sowing rate on population dynamics,water consumption,canopy photosynthetic characteristics,yield and quality formation of wheat were studied at five levels of 75kg·hm-2,150 kg·hm-2,225 kg·hm-2,300 kg·hm-2and 375 kg·hm-2.The main results are as follows:(1)During the overwintering booting period,the soil water storage of 0-100 cm decreased with the increase of sowing amount,and the highest sowing amount was 75 kg·hm-2,but there was no significant difference between the treatments of jointing and booting,150 kg·hm-2and 225 kg·hm-2;the highest sowing amount was 150 kg·hm-2in the flowering period,which was significantly higher than other treatments;the highest sowing amount was 300 kg·hm-2in the mature period is the highest and 150 kg·hm-2is the lowest.In the early and middle stage of wheat growth,the soil water storage was significantly higher than that of other treatments in 75 kg·hm-2and 150 kg·hm-2,which decreased rapidly in the flowering maturity stage and was consumed rapidly by wheat in the later stage.With the increase of sowing amount,water use efficiency first increased and then decreased,with the highest sowing amount of 150 kg·hm-2,which was significantly different from other treatments,reaching 17.27 kg·hm-2·mm-1,8.55%-37.72%higher than other treatments.(2)The number of tillers in the population was the highest at 375 kg·hm-2,which was significantly higher than other treatments,and the lowest at 75 kg·hm-2.At booting maturity stage,150 kg·hm-2was significantly higher than other treatments.It can be seen that high or low seeding rate is not conducive to the increase of tiller number in the middle and later stage of dry land wheat growth.The suitable sowing amount optimized the tiller number and leaf area index of the population.In the early and middle stage of growth,the reasonable leaf area index can be constructed and the effective light radiation of the canopy can be effectively intercepted.In the process of post anthesis grouting,the aging of the functional leaves is relatively delayed and the photosynthetic performance is prolonged,which is conducive to the grain filling of wheat in dry land.Compared with other treatments,the sowing rate of 150 kg·hm-2significantly increased the tiller number,leaf area index and dry matter accumulation of wheat population,which was more conducive to building a reasonable population,promoting the growth of wheat and improving the final yield.(3)The proportion of nitrogen transfer from plant to grain reached about 80% at maturity,while the amount of nitrogen accumulation was the lowest in leaves and rachis + glume.Among them,pre anthesis transport accounts for 75%-84% and post anthesis transport accounts for 16%-25%,indicating that nitrogen transport mainly depends on pre anthesis.The nitrogen transport rate of 150 kg·hm-2before anthesis was84.37%,1.04%-12.95% higher than that of other treatments,which promoted the increase of the proportion of nitrogen accumulation in the seeds of the plants and the efficient transport of nitrogen accumulation,which was beneficial to the increase of protein yield;the nitrogen transport rate,nitrogen absorption efficiency,nitrogen harvest index and nitrogen production efficiency of 150 kg·hm-2before anthesis were higher than those of other treatments.(4)The plant height,ear length and number of fertile spikelets increased first and then decreased with the increase of sowing amount,and the highest sowing amount was 150 kg·hm-2.150 kg·hm-2can increase plant height,spike length per plant,number of fertile spikelets and filling rate,and then promote yield.Compared with other treatments,the number of spikes was increased by 0.66%-29.66% and the number of grains per spike was increased by 5.59%-23.35%,but the difference of 1000 grain weight was not significant,and the average yield increase was 21.9%.(5)With the increase of sowing rate,the content and yield of albumin,globulin,gliadin,gluten,protein all increased first and then decreased,and the highest sowing rate was 150 kg·hm-2,and the effect of soluble protein content in the middle and late filling stage was obviously improved.150 kg·hm-2was more beneficial to the formation and enrichment of soluble sugar content,sucrose content and starch content.Under the condition of 150 kg·hm-2,the peak viscosity,the low viscosity,the relaxation value,the final viscosity,the rebound value and the gelatinization temperature were all higher than those of other treatments.In a word,150 kg·hm-2is more suitable than other treatments to construct a reasonable population,balance the water consumption in each growth stage,and help to coordinate the distribution of water and improve water use efficiency.Suitable sowing quantity can promote the number of tillers in the middle and later stage of the population,help to build a reasonable population,promote the growth of wheat,improve plant height,optimize the photosynthetic performance of the population,facilitate the accumulation of dry matter quality,and improve the yield mainly through the number of ears.The suitable sowing rate could promote the proportion of nitrogen accumulation and high-efficiency transportation in the whole plant,and the suitable sowing rate could improve the secondary processing quality of dryland wheat higher than other treatments,so as to achieve the simultaneous improvement of yield and quality.