| With the adjustment of the planting industry structure in southern mountainous area of Ningxia,the expansion of potato planting area has driven the development of the industry,and the ecological risks that followed had become prominent increasingly.The experiment were carried out with single potato(P),single corn(M),single broad bean(B),potato and corn intercropping(P‖M),and potato broad bean intercropping(P‖B),and through continuous experiments in 2017 and 2018.The growth and development,physiological characteristics,nutrient absorption and yield effects of potato under different planting patterns provide a scientific basis for rational intercropping of potato in southern mountainous area of Ningxia.The research found that:1.The growth and development of potato in the intercropping mode were significantly different from that in the single cropping.The results of two years showed that P‖M treatment can promote the accumulation of dry matter in the early stage of potato compared with P treatment.In the first half of the period,P‖M treatment>P treatment>P‖B treatment,P‖B treatment decreased relatively in the early and middle stages,and later increased.At the maturity of 2017,the P‖B and P‖M treatments were 43.03%higher and 11.65%higher than the P treatment,respectively.In 2018,the P‖M treatment in the tuber expansion period was higher than that of P treatment and P‖B treatment,which was 93.65%and 81.22%.The quality of above-ground dry matter in the P treatment and P‖B treatment at maturity was 74.3%and 82.21%higher than that in the P‖M treatment,and the difference was significant.The leaf area index P‖M treatment showed an increasing trend in the middle stage,while the late stage decreased rapidly.The P‖B treated leaf area index was lower than the P treatment in the early and middle stages,and the late stage was slower than the P and P‖M treatments.In 2017.the leaf area index of P-treated and P‖M-treated potato in tuber expansion period was 35.39%and 43%higher than that of P‖B treatment.In 2018,the leaf area index of P-treated and P‖M-treated potato in tuber expansion period was 106.22%and 126.09%higher than that in P‖B treatment.The leaf area index of P-treated and P‖M-treated potato in starch accumulation period were 125.49%and 197.63%higher than that in P‖B.2.Compared with single-cropped potato,the physiological index of intercropped potato were changed.In 2018,the relative chlorophyll content(SPAD)of potato leaves treated with P‖M treatment and P‖B treatment was 16.51%and 7.9%higher than that of P treatment,which reached significant difference(P<0.05).The initial fluorescence(Fo)and photosynthetic index(PI)in the chlorophyll fluorescence index of P‖M treated potato leaves increased.In potato seedling stage that PIM treatment and P‖B treatment could significantly increase the net photosynthetic rate of potato(Pn),stomatal conductance(Gs),transpiration rate(Tr);PAR values of P‖B treated potato measured at 20 cm fron the starch accumulation period were 31.82%and 53.47%higher than P treatment and P‖M treatment,reaching significant difference level(P<0.05);3.Compared with single cropping,potato has different absorption and utilization of nitrogen,phosphorus and potassium in intercropping mode.The results of two years showed that P‖M treatment were beneficial to potato nitrogen accumulation in the early stage and P‖B treatment in the later stage.At the harvesting stage that the absorption of nitrogen by the potato:P‖B treatment>P‖M treatment>P treatment,measured in the 2018 harvest period,the P‖B treatment of potato plants nitrogen content ratio P‖M treatment,P The treatments were 16.85%higher and 15.82%higher respectively.The difference between P‖B treatment and P treatment reached a significant level.For phosphorus absorption:P‖B treatment>P treatment>P‖M treatment,P‖B treatment of potato leaves with higher phosphorus content P treatment,P‖M treatment 28.86%,34.58%,reached a significant level;for potassium absorption:P‖B treatment>P‖M treatment>P treatment.The nutrient harvest index showed that compared with the broad bean and corn,potato organ formation was less utilized for nitrogen and phosphorus,and for potassium utilization,the potato had the lowest nitrogen harvest index and higher potassium harvest index.4.There was a significant difference in intercropped potato yield compared to single cropping potatoes.The yield of potato in 2017:P‖B treatment>P‖M treatment>P treatment and the yield of potato in 2018:P‖M treatment>P‖B treatment>P treatment,the intercropping results are more than single cropping.Intercropping treatment The difference in yield between the years may be caused by climate anomalies in 2018.In 2017,P‖M processed LER<1,while P‖B processed LER>1.In 2018,P‖M processed LER>1,while PIB processed LER<1,and two years of data showed that the potato was at a competitive disadvantage.5.Compared with monoculture,soil total nitrogen,alkali nitrogen and organic matter content in the intercropping mode increased significantly compared with monoculture.P‖M treatment and P‖B treatment of soil alkali nitrogen content compared with P treatment.It is 10.48%higher and 7.74%higher,reaching a significant level.The soil organic matter content of P‖M treatment and P‖B treatment was 8.74%and 6.78%higher than that of P treatment,reaching a significant level.The available phosphorus content of soil in P‖M treatment increased significantly,but the available potassium content decreased,and the total phosphorus content in P‖B treatment decreased significantly. |
