Study On Coupling Effect Of Water And Fertilizer Of Atriplex Canescens Under Drip Irrigation

To explore the reasonable water and fertilizer management methods of Atriplex Canescens,this experiment begins from June,2020.Pot experiment is applied,while binary quadratic orthogonal combination design is used to conduct 2 factors and 3 levels experiment.The three drip irrigation water volumes were 142mm（W1）,217mm（W2）and 292 mm（W3）respectively;Three levels of fertilization:F1（N-P₂O₅-K₂O=200-170-60 kg/hm²）,F2（N-P₂O₅-K₂O=240-200-120 kg/hm²）and F3（N-P₂O5-K₂O=280-230-180 kg/hm²）with a total of 9 treatments.Through observing the growth of Atriplex Canescens and testing the basic physical and chemical properties of the soil,the effects of water and fertilizer coupling on the growth of Atriplex Canescens and the physical and chemical properties of the soil were explored.The main conclusions are as follows:（1）Coupling of water and fertilizer has significant influence on the ground part of Atriplex Canescens.During the whole experiment,the plant height,stem diameter and leaf number of Atriplex Canescens grow the best in August,which is obviously better than other months.Excessive irrigation and fertilizer have a repression effect on its plant height,stem diameter and leaf number.In middle water condition,the data of plant height,stem diameter and leaf number is the most.Reasonable water and fertilizer can improve the yield of chlorophyll content in leaf.The chlorophyll content processed by W2F2 is the highest,followed by W2F3,and the biomass per plant processed by W2F3 is the most.Therefore,reasonable water and fertilizer can increase the chlorophyll content in leaf,accelerate the growth of Atriplex Canescens,and improve the yield.（2）The diurnal variation of photosynthetic characteristics of leaves is as follows:There were two peaks at 12:00 and 16:00 in each treatment.The net photosynthetic rate Pn of W2F2 treatment was significantly higher than that of other treatments,and the transpiration rate Tr and stomatal conductance Gs of W2F3treatment were significantly higher than those of other treatments.Under the same fertilization amount,the order of net photosynthetic rate,transpiration rate and stomatal conductance is:medium water>high water>low water.（3）Under the same fertilization amount,the salt content decreased with the increase of irrigation amount,and under the same irrigation amount,the salt reduction rate increased first and then decreased with the increase of fertilization amount.With the increase of irrigation amount,PH value decreased at first and then increased.The change trend of organic matter,alkali-hydrolyzable nitrogen,available phosphorus and available potassium in soil was mainly as follows:it increased with the increase of fertilization,and increased first and then decreased with the increase of irrigation amount.（4）Through the analysis of the regression model equation,it was found that the effect of water and Fertilizer on the yield of Atriplex canescens was water effect>fertilizer effect.The calculation showed that the yield of Atriplex Canescens reached the maximum of 212g/plant when the irrigation amount=223.28mm,and the fertilizing amount（N-P₂O₅-K₂O）=278-231-139（kg/hm²）.