Effects Of Different Light Control And Irrigation Amount On Growth Characteristics And Water Consumption Rule Of Maize

Light and water are essential natural resources for crop growth and development.It is an important factor affecting photosynthesis,growth and development,yield and quality of crops,and also affects the water consumption of crops.In order to explore the effects of different light and irrigation conditions on the growth characteristics and water consumption patterns of summer maize,this study uses natural light as the control(Lek),and uses black sun shading net to achieve three light control treatments,which were 21%(L21),55%(L55)and 77%(L77)respectively,at the same time,the conventional irrigation volume(Wck)was set under Lck,L21 and L55 light control,70%conventional irrigation(W70),50%conventional irrigation(W50)three kinds of irrigation water treatment,the effects of different light control and irrigation conditions on the growth index,yield,grain quality,water consumption law and water use efficiency of summer maize were studied in the 2016-2017 year experiment station in Xi'an Weiyang District.The main results obtained are as follows:(1)The canopy temperature and soil temperature decreased with the increase of lig-ht intensity,and the relative humidity of canopy increased.Light control has a good inhi bitory effect on the evaporation of summer corn.The reduction effect of L21Wck,L55W ck and L77Wck on the evaporation of summer maize is 14.9%,29.2%and 42.4%respec tively,and there is a good linear relationship.Under the same light control condition,the effect of evaporation increased with the increase of irrigation volume.(2)Soil moisture at different soil depths varied at different growth stages of summer maize,and soil moisture in 0-30cm soil layer changed most severely during the whole growth period.Under controlled light,soil moisture of summer maize 0-100cm increased,compared with LckWck treatment,L21 Wck,L55Wck and L77Wck treatment increased average 4.2%,5.4%and 6.6%for two years.Under the same light control condition,soil moisture increased with the of the summer corn water consumption,of which the effective rainfall and irrigation amount are the main components,accounting for more than 88.7%of the total water consumption.The water consumption of summer maize decreased linearly with the increase of control light,and increased linearly with the increase of accumulative irrigation.It showed that light control could reduce summer corn water consumption,and irrigation could increase summer corn water consumption.Water consumption in different stages of summer maize is different,and milk maturity is the critical period of water consumption.(4)The growth and development of summer maize were affected by different light control and irrigation treatments.Two years data showed that the growth of summer maize was slow and the growth period was delayed after high light treatment and low irrigation.The plant height,leaf area and stem diameter also decreased with the increase of light control degree and irrigation volume.The dry matter accumulation of summer maize was better than that of the Logist model with the growth time,and the distribution of dry matter in stems,leaves,top flowers,spikes,bracts and the accumulation of total dry matter were reduced.The distribution of dry matter in stem,leaf,top flower,spike,bract and total dry matter accumulation were all greater than that of low irrigation.(5)The content of crude protein and the content of starch and crude fat decreased.As the amount of water increased,the content of grain crude protein decreased,the content of starch increased,and the change of crude fat content was not obvious.Light treatment reduced the spike length and ear thickness of summer maize,increased the bald tip length,reduced 100 grain weight,plant weight,grain number per spike and theoretical yield.The difference of ear length,ear diameter and bald tip length of Summer Maize Treated by different irrigation amount was not obvious.The water use efficiency of Summer Maize Treated with L77Wck was the lowest in two years,and the water use efficiency of L21W50 was the largest.With the increase of light control,the water use efficiency of the summer corn decreased with the increase of light control,and the greater the amount of water control in the same light control condition,the less water use efficiency of summer maize.It was suggested that the appropriate control of irrigation water under low controlled light conditions could effectively improve the water use efficiency of summer maize.