| As a new type of irrigation,micro-spray irrigation can save water,fertilize and spray pesticides,and can prevent wheat from drying dry.Therefore,compared with traditional irrigation methods,micro-spraying is used to irrigate wheat.Very broad application prospects.In order to study the effects of micro-spray irrigation quota and irrigation times on water consumption,growth physiological indexes and yield of spring wheat in Hexi region,a field experiment was conducted at Shiyanghe Experimental Station,China Agricultural University,Wuwei,Gansu Province from March 2017 to August 2017..The test was conducted with"Yongliang No.4"as the test variety.The irrigation quota is set at three levels of 300 mm,350 mm and 400 mm,which are recorded as M300,M350 and M400.Under the irrigation quota,three different irrigation times were set up for 5 times,7 times,and 9 times,which were recorded as N5,N7,and N9,for a total of 9 treatments.By studying the effects of different irrigation combinations on the growth,physiological status,water consumption characteristics and yield of winter wheat,the following main conclusions were drawn:(1)Under different irrigation treatments,the water consumption in each growth period and the whole growth period is positively correlated with the irrigation quota,and there is no significant difference between the water consumption and the total water consumption in each treatment stage under different irrigation times.Under different irrigation times,the spatial distribution of water in all irrigation treatments generally follows a similar pattern.The surface soil moisture content is N9>N7>N5,and the distribution of deep soil moisture is reversed,that is,N9<N7<N5.Under the local geographical and climatic conditions,the basic trends of evapotranspiration during the growth period of spring wheat with micro-sprinkler irrigation were:tillering stage-jointing stage>heading stage>filling stage-maturity stage>seedling stage.The basic trends of water consumption intensity are:heading stage>tillering stage-jointing stage>filling stage-maturity stage>seedling stage.(2)The results showed that the total dry matter accumulation during the growth period of wheat increased first and then decreased with the increase of irrigation quota,reached the maximum at M350,and continued to increase with the increase of irrigation times,reaching the maximum at N9.The rapid growth period of dry matter accumulation is the longest at M300.Water stress can prolong the rapid growth period of wheat dry matter,and the rapid growth period is negatively correlated with the number of irrigation times.The more irrigation times,the shorter the rapid growth period.In addition,the maximum rate of dry matter accumulation of wheat also increased first and then decreased with the increase of irrigation quota,and continued to increase with the increase of irrigation times.The leaf area index does not increase with the increase of irrigation quota.The appropriate irrigation quota can keep the leaf area of wheat at a high level throughout the growth period,and the leaf wilting in the later stage is slower than other treatments.For this experiment,the number of irrigations was positively correlated with the wheat leaf area index,and 9 irrigations were more conducive to the growth of wheat leaf area.Similar to the leaf area,the plant height did not increase with the increase of irrigation quota,but it was positively correlated with the number of irrigation.Suitable soil moisture conditions could prolong the vegetative growth time of wheat to some extent.The M350N9 treated irrigation combination is most suitable for the growth and maintenance of wheat leaf area and plant height.(3)The chlorophyll content of wheat flag leaves increased with the increase of irrigation times,but the increment was gradually reduced.For this experiment,the chlorophyll content of flag leaves increased with the increase of irrigation quota,and water stress promoted the early maturity of wheat,and the chlorophyll content decreased significantly,and better water conditions could delay this phenomenon.The response of Pn,Gs,and Tn to irrigation quotas and irrigation times is very similar.All three increased with the increase of irrigation quota,and the growth rate is gradually decreasing.Pn,Gs and Tn decreased with the decrease of the number of irrigation times under the same irrigation quota.Under M300 treatment,the decline of photosynthetic rate of wheat flag leaves was mainly restricted by non-stomatal factors.Under the treatment of M350 and M400,the decline of photosynthetic rate of wheat flag leaves was mainly restricted by stomatal factors.(4)With the increase of irrigation quota,the wheat yield increased first and then decreased,and the output of M350 was the highest.Under the same irrigation quota,the variation trend of yield is N9>N7>N5.The M350N9 yields 7973 kg/hm~2,the highest of all treatments.Under different irrigation quotas,the relationship between water use efficiency is M350>M300>M400.Under different irrigation times,the change law of water use efficiency is consistent with the yield,that is,N9>N7>N5.The M350N9 has a water use efficiency of 1.96 kg/m~3,the highest of all treatments.Therefore,for this experiment,the spring wheat has a water intake of 350 mm throughout the growth period,and 9 irrigations are the most suitable irrigation combination for water saving and efficiency improvement. |
