| Aiming at the problems of drying with little rainfall and strong evaporation in Tongxin County,Ningxia and low water and nitrogen use efficiency of potatoes in dry land,different test combinations of different irrigation quotas(W1:1050 m3/hm2,W2:1500 m3/hm2,W3:1950 m3/hm2)+buried depths of seep-irrigation(D1:0 cm,D2:10 cm,D3:20 cm)and different irrigation quotas(W1:1050 m3/hm2,W2:1500 m3/hm2,W3:1950 m3/hm2)+nitrogen rate(N1:120 kg/hm2,N2:180 kg/hm2,N3:240 kg/hm2)were set up in order to analyze the effects of different combinations on potato growth index,water use efficiency(WUE)and nitrogen partial factor productivity and study the growth and development of potato and water and nitrogen use efficiency.Principal Component Analysis(PCA)was used to comprehensively evaluate the observed values of various indices in different treatments of potato seep-irrigation,so as to determine key technical indices such as buried depth of see-irrigation pipe,irrigation quota and nitrogen rate suitable for potato planting in this area.The main results are as follows.The experimental result of the effects of seep-irrigation with different buried depths on potato growth and development showed that:Under the same irigation quota,the dry matter quantity and yield of potatoes treated with D2 and D3 were significantly higher than those treated with D1,and the WUE of potatoes treated with D2 was significantly higher than those treated with D1.Under the same buried depth of seep-irrigation,the WUE of potatoes treated with W2 was significantly higher than those treated with W1.The commodity rate(82.32#%)and WUE(14.86 kg/m3)of potatoes treated with W2D2 were the highest.The dry matter quantity(179.54 g/Plant)and yield(42.98 t/hm2)treated with W3D2 were the highest.The experimental result of the effects of water and nitrogen allocation on potato growth and development under seep-irrigation conditions showed that:Under the same irrigation quota,the dry matter quantity,yield and WUE of potatoes treated with N2 were significantly better than those treated with N1,and the nitrogen partial factor productivity of potatoes treated with N1 and N2 was significantly higher than those treated with N3.Under the same nitrogen rate,the stem diameter,yield and nitrogen partial factor productivity treated with W2 and W3 were significantly higher than those treated with W1.The dry matter quantity of potatoes treated with W2 was significantly higher than those treated with W1,and the WUE of potatoes treated with W1 was significantly higher than those treated with W2 and W3.In 2018,the W2N2 treated potatoes had the largest dry matter quantity(174.37 g/Plant),W1N1 treated potatoes had the highest WUE(10.86 kg/m3),W3N2 treated potatoes had the largest yield(42.56 t/hm2),and W3N1 treated potatoes had the highest nitrogen partial factor productivity(316.33 kg/kg).The comprehensive evaluation of the effects of seep-irrigation with different buried depths and water and nitrogen allocation on potatoes showed that:W2D2 treatment had the highest comprehensive evaluation value in the experiment of seep-irrigation with different buried depths and irrigation quota,and 10 cm was the best buried depth of seep-irrigation.The comprehensive evaluation value of W2N2 treatment was the highest in the experiment of different water and nitrogen allocation of potato under seep-irrigation conditions.The irrigation quota of 1500 m3/hm2+ nitrogen rate 180 kg/hm2 was the best combination of irrigation and nitrogen rate for seep-irrigation under the condition of 10cm depth of total seepage pipe.Through field experiments,the optimal buried depth of potato seep-irrigation with total seepage pipe is determined to be 10cm.The optimal combination scheme of water and nitrogen suitable for potato seep-irrigation in this area is screened out,which provides a theoretical basis for cash crops such as potatoes planted under seep-irrigation in the dry land of Tongxin Country,Ningxia. |
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