Effects Of Phosphorus Nutrition On P Absorption And Yields Of Soybean

Soybean has much rich nutritional value and soybean production has important significance in improving the people’s food structure,meeting the requirements of protein and fat, as well as the development of animal husbandry and the food industry. Phosphorus is one of the necessary nutrient for growth and development of soybean plant,which participate in a variety of biochemical processes with many ways and play an important role in promoting soybean growth and metabolism.Studies on the phosphorus absorb accumulation and distribution regulation in the soybean plant are implications of phosphorus fertilizer application, reduction of production cost, and increase in yield for soybean.This work was conducted from2010to2011with frame experiment (pot without bottom) and sand culture experiment in the experimental station of Northeast Agricultural University (NEAU).The experiment was divided into two parts of phosphorus nutrition experiment and cut phosphorus experiment,as the phosphorus nutrition experiment was conducted by the way of combining with frame and sand culture,and the nutrient solution of the sand culture experiment was setted respectively seven phosphorus level of1,11,21,31,and41,5land61mg/L,and the frame experiment was setted5phosphorus level,their soil available phosphorus content were5.68,l6.68,23.47,26.62,31.37mg/kg respectively;the cut phosphorus experiment was divided into cutting phosphorus according to the growth period and cutting phosphorus every15days stage experiment, which was conducted by the way of sand culture,as it had a systematic study about the phosphorus absorb,accumulation, and distribution, transfer regulation. Results were shown as follows:Phosphorus accumulation center changed as the soybean grew.Phosphorus accumulation of leaf was obvious higher than that of handle and stem, leaf segment was the phosphorus accumulation center at vegetative growth stage,next one was root;when soybean turned to reproductive growth,phosphorus accumulation transferred to legume from vegetative organs,the phosphorus accumulation of leaf, handle,stem and root decreased.Phosphorus accumulation of soybean vegetative organs was most fast during the blooming period to the beginning pod period,and in the priod of seed phosphorus accumulation was most. When soybean was lack of phosphorus, phosphorus was transferred to the top of soybean organs from the middle and lower part of soybean,and firstly transferred to the growing organs of soybean;during the period of reproductive growth,phosphorus was transferred to the pod mostly, in order to guarantee the needs of the pod for phosphorus.The promoting role of the higher phosphorus nutrition levels on the phosphorus concentrations and phosphorus absorption of soybean was obvious at early and medium stages,and soybean plant phosphorus absorption was increased continually under the increase of phosphorus nutrition at the beginning of blooming (R,).When the phosphorus level was51mg/L,the promoting role of the phosphorus nutrition was not obvious at the beginning of seeding (R5).When the phosphorus nutrition level was31mg/L, the promoting role on soybean phosphorus absorption of the phosphorus nutrition was not obvious at the full maturity (R8).When the phosphorus nutrition level was increased, the soybean yield showed a single peak curve and the yield was the highest when the phosphorus nutrition level was31mg/L. Soybean yield increased obviously While the phosphorus nutrition was lower than31mg/L;there was no benefits to increase yield, or even inhibition yield while the phosphorus nutrition was higher than31mg/L.When the phosphorus nutrition level was increased, the kernel number of a plant showed a single peak curve too, and the kernel number was the largest when the phosphorus nutrition level was21mg/L. When the phosphorus nutrition level was the lowest (P1), the kernel number and the node number were the least, while the weight of100seed was the largest. While the phosphorus nutrition was achieved to31mg/L,the promoting role in plant height of going on increasing the phosphorus nutrition was not obvious;the influence of phosphorus levels on soybean node number was smaller.and it could lead to decrease soybean node number only While phosphorus nutrition was lower than31mg/L. Before the beginning seeding of soybean,the phosphorus nutrition level was the key factor of forming yield, and after the beginning of seeding, the yield was insensitive to the phosphorus nutrition.The node number and kernel number were decreased under no phosphorus nutrition duringV3～R1and R1～R5stages,while the vegetative of plant was not obviously affected,and the yield and phosphorus absorption were decreased obviously.The phosphorus concentrations of vegetative,pod skin and seed and phosphatic absorption of seed were exclusively affected under no P nutrition during R5～R7stages,while the effect on the yield was not obvious.The effect of phosphorus fertilizer on increasing soybean yield was different because the soil organic phosphatic level was different.In the five available phosphatic level of soil,there was a increasing role on yield while soybean seed was fertilized phosphatic fertilizer,but the increased yield degree was the best when the soil of available phosphorus were5.68mg/kg,and the increased yield degree decreased obviously while the soil of available phosphorus was higher than16.68mg/kg.