Corn / Soybean Intercropping, Crop Rhizosphere Nutrient Efficient Use Of The Mechanism

The intercropping cultivation is a fanning measures which is gradually known and grasped in the long-term production practice .its characteristic is fully using the resources and raising the output in large scale .Choosing the appropriate crops to carry on intercropping may enhance the efficiency of crops using the nitrogen phosphorus. Therefore the intercropping has the vital practical significance in the solution population, alleviation the resources dry up day by day and ecological environment worsening and so on. It attracts the attention of agronomist and ecologist more and more. taking the corn/soybean intercropping as the object, This research based on the field experiment and the pot culture , systematically studied rhizosphere soil's mineral substance nutrient content, rhizosphere soil's microorganism quantity and the biochemistry intensity, the root system's shape and activeness, the crops' biology output and the economic output etc on the corn and the soybean.Five kind of patterns is designed in pot culture experiment, respectively is: system corn/soybean intercropping 1 (i.e. corn and soybean root system are separated with the plastic film, only the aerial parts strive for light and hot resources, the underground parts does not have the mutual exchange between moisture and nutrient, The root system cannot carry on the interaction), system corn/soybean intercropping 2 (i.e. corn and soybean root system are separated with the 30um nylon net, not only aerial parts strive for light and hot resources, but also underground portion has mutual exchange between moisture content and nutrient, but root system doesn't interact each other), system corn/soybean intercropping 3 (i.e. corn and soybean are not separated, aerial parts strive for light and hot resources, moreover underground portion also has mutual exchange and competition between moisture content and nutrient, root system can interact),monocropping corn and monocropping soybean five planting patterns. three kind of patterns in the field experiment is designed: corn/soybean intercropping, monocropping corn and monocropping soybean .The results indicated that:1 during the whole growth period,the dynamic change of rhizosphere soil's microorganism quantity and enzyme activity is the earlier period low, the intermediate stage high, later period reducing , shaped "inverse V". The reason is under the condition of corn/soybean intercropping and when the root system interact each other, the root system's shape and activeness strengthen, and in the prime season of growth ,crops' demanding more nutrient also causes soil microorganism and the enzyme activity obviously increase. Thus transform organic nitrogenous phosphorus that the plant can't directly absorb and use to inorganic nitrogen phosphorus that the plant can directly absorb, promotes the available nutrient content in rhizosphere soil to increase, enhance the efficiency crops absorbing and using the available nutrient in rhizosphere soil2 under the corn/soybean intercropping condition, during the whole growth period,the dynamic change of rhizosphere nutrient content is the earlier period high, the intermediate stage low, later period reducing , shaped "inverse V". The reason is when crops need more nutrient , the rhizosphere nutrient content reduces, and when the crops need small even no longer need the nutrient, the rhizosphere nutrient content rises. rhizosphere soil ulmin, the alkaline hydrolysis nitrogen, the effective phosphorus content of the intercropping corn and the intercropping soybean is higher than correspondingly monocropping crops. Looking from the different processing mode, when the corn and the soybean root system completely interact each other, the crops' rhizosphere soil's nutrient content is lower than correspondingly monocropping crops and that of plastic membrane separation. The corn/soybean intercropping displays the obvious intercropping superiority in the soil nutrient valid aspect.3 under the corn/soybean intercropping condition, the efficiency of intercropping absorbing corn nitrogen phosphorus potassium is also obviously higher than the monocropping corn and that of separated with plastic membrane; in the whole growth period,the root system' shape and activeness of intercropping corn is obviously higher than the monocropping corn and that of separated with plastic membrane. The root system shape and the efficiency absorbing nitrogen phosphorus potassium of the intercropping soybean is lower than monocropping soybean, but this does not affect its normal growth.. The entire intercropping system displays the superiority in nutrient absorption and useing, the nutrient resources is used highly effectively.4 under the corn/soybean intercropping condition,when the crops root system interacts each other, the intercropping corn displays the intercropping superiority, Its adult plant is big, the root system is developed, root system activeness strengthens, rhizosphere soil's microorganism quantity and the enzyme activity enhances, The ground biology output and the economic outputs are all higher than monocropping corn and that of separated with plastic membrane. But the intercropping soybean is lower than monocropping soybean. Looking from the entire synthesis benefit of system intercropping corn/soybean, the benefit of intercropping system is higher than that of monocropping system, the entire intercropping system displays the intercropping superiority.