Study On Productivity In Spring Maize Ⅱ Soybean Super Wide-narrow Intercropping System

Intercropping system could utilize resources more efficiently and increase yields siganificantly.Green manure plays roles on soil fertilization, chemical fertilizer replacement, yield increase, etc. Maizeis a major crop in China. It is a worthy direction to explore the possibility of high yields for both maizeand legumes by the way of more reasonable spatial allocation. A winter green manure-spring maize‖soybean super wide-narrow intercropping pattern was established in North China, in which, legumeswere planted in the wide row of2.2m, while maize was planted in the narrow row of0.5m. Maizedensity in this pattern was the same as that in monoculture pattern by regulating the individual spacing.In this experiment, the nutritional and photosynthetic characteristics were studied for this intercroppingpattern under different fertilization treatments after green manure plantation. The green manure wasFebuary Orchid (Orychophragmus violaceus). Four fertilization levels were0%,60%,80%and100%of normal amount, respectively. Monoculture maize with100%fertilization amount was also includedas a contrast. The main results were as follows:1. Maize yields in intercropping and monoculture pattern were almost the same. Under the samefertilization condition (100%fertilization amount, no green manure), maize yields in intercropping andmonoculture were8346and8309kg/hm2, respectively. In intercropping system, besides the maize yield,the soybean yield was910kg/hm2.2. Yield, biomass and nutrient accumulation of both maize and soybean showed increasing trendswith the addition of fertilization amount. Soil inorganic nitrogen, available phosphorus and potassiumincreased with the increase of fertilization amount. Individual leaf area, net photosynthetic rate (Pn),stomatal conductance (Gs) and intercellular CO2concentration (Ci) of maize also showed increasingtrends with the addition of fertilization amount at the same growth stage.3. Green manure application could improve the yields of both maize and soybean, especially forsoybean, and could replace about20%of chemical fertilizer in the system. Compared with no greenmanure, maize yields in the green manure treatments were almost the same under100%and80%fertilization amounts, while the yield was increased by810kg/hm2(10.68%) at the60%fertilizationlevel and increased by1408kg/hm2(23.67%) when no fertilization. The soybean yields under the4fertilization levels with green manure application were all enhanced significantly by14.54%to34.62%.Green manure application could improve the photosynthetic capacity of maize at later growth stages,net photosynthetic rate and stomatal conductance were enhanced at the tasseling and filling stages.4. Intercropping and green manure application could promote N, P, K accumulation of maize andsoybean. Under100%level of fertilization, compared with that of the monoculture pattern, the Nabsorptions of the intercropping system without and with green manure were increased by121.19and156.11kg/hm2; the P absorptions were increased by7.38and11.77kg/hm2; the K absorptions wereincreased by103.81and163.03kg/hm2.5. The super wide-narrow intercropping pattern coud form a better field condition, which improved photosynthetic conditions of maize at late growth stages. Compared with the monoculture pattern ofsame fertilization amount, the photosynthetic condition in intercropping pattern was better at criticalstages of yield formation (filling stage to dough stage), with higher photosynthetic rate and bigger leafarea. In addition, the super wide-narrow intercropping pattern improved the light transmittance ofcanopy and enhanced the light interception by maize leaves. The light condition of soybean in thispattern was also nice enough and the soil temperature increased as well.