Effect Of Irrigation With Slight Saline Water And Drop Irrigation On Rain-fed Maize Growth,Water And Salt Dynamics

How to utilize saline water reasonably,scientificly,efficiently and safely has always been a core problem in farmland irrigation.In northwest,because of lack of water resources and ecological environment getting worse,we must increase the water-use efficiency,go the way of the development of water-saving.Develop water-saving irrigation agriculture is now fundamentally get rid of the water crisis in northwest China,to ensure agricultural sustainable development path.Based on the relative research about saline water irrigation and drip irrigation both at home and abroad,this paper studied on the effect of the saline water on typical crops growth,as well as related water saving method.The main results are as follows:(1)Through study the effect of mineralization salinity water irrigation and soil salt content on corn emergence rate and emergence time,we found that when the mineralization of water over 3.0 g/L,which can inhibition com emergence rate and delay time of maize emergence;Initial soil salt content too high was bad for maize emergence,but when the salinity of irrigation water and the salt content of soil was about the same,the effect of irrigation water salinity on corn seedling emergence rate and emergence time significantly greater than the initial soil salt content;When the irrigation water salinity and initial soil salinity increased,maize plant height showed a reduce trend gradually;At maize spike and mature periods,mineralization water irrigation can improve the com yield effectively,but corn kernels and the total output decreased with the increased of water salinity;The inhibitory effect of irrigation water salinity on maize dry matter accumulation was significantly greater than the initial soil salt content(2)After different mineralization salinity water irrigation,soil salinity was significantly higher than before irrigation,With the increased of irrigation water salinity,soil salt content increased significantly;When use 3.0 g/L mineralization salinity water irrigation,the change trend of soil salt content was the same as fresh water treatment before or after irrigation,but amplitude of variation more than fresh water.Three years of irrigation experiments showed that using 3.0 g/L of mineralization salinity water irrigation,0 to 40 cm soil had no significant phenomenon of salt deposition,the average salt content in 0 to 120 cm soil layer maintain a balance in a year or in interannual.With 4.0 g/L mineralization salinity water irrigation,soil secondary sanitization occurred in the third year after irrigation,the average soil salt content in 0-120 cm soil layer increased year by year,the soil in a salt deposition state,but when the soil salt content increased to a certain degree in taproot layer,it no longer increase,the layer became the salt conduction zone Based on the study on the soil salt contents of 0-120 cm in the soil profile after salinity water irrigation,the results showed not all the salt will concentrate between the soil profile of 0-120 cm,of which some will absorbed by the plant,furthermore,most part will be leached by irrigation water or the rainfall.During the whole period,the salt content in the soil profile of 01-20 cm decreased with salinity increasing.Moreover,the higher the salinity,the more the salt will be leached and absorbed.(3)Based the experimental study on evaporation rate in corn field,the irrigation water amount of all the growth periods have similar effect on the evaporation rate in the corn field.The main results are as follows:the consumption of water is the largest with the largest water irrigation amount;however,the consumption will decrease with the irrigation amount.All the irrigation water amount treatment have great effect on the thousand-grain weight and productivity,moreover,the effect became much more obvious when the irrigation water amount is very low.Evaporation is the main way that the water was lost during the shooting periods of the com and soil water in the surface is obvious lower than that of any other profile(20-40 cm and 40-60 cm).So if the membrane tectonic was not conducted in the corn field,the water will lost a lot through evaporation and the soil water content decrease.The soil water content increased during the and grout filling and maturity period which will be help with the soil water reserve.The experimental studied on cheap dripping system with the waste plastic bottle were studied and the main results showed as follows.When the orifice diameter was between 1.0-2.5 mm,the simple drip irrigation system could be used in the soil with large porosity,such as sandy soil;while when the orifice diameter was between 3.0-6.0 mm,the simple drip irrigation system could be used in the soil with good percolation;however,when Orifice sizes is above 6.0 mm,the simple system were found to be unsuitable.The report recommended that the system should be popularized among rural farmers who should be motivated with incentives that may be commensurate to their waste disposal service.