| A good configuration of farmland ecosystem which was under the influence of land ecosystem and human control system was the precondition of sustainable development. This paper analysised those index namely dry matter accumulation, nutrient accumulation and the change of soil nutrients of maize-soybean relay intercropping systems pattern, exploring the differences of material flow and environment economic benefits using the method of emergy in the field location experiment, the relay-intercropped maize(M) and the relay-intercropped soybean(S) as control group. set two levels of fertilization:the application of P(P:maize 105 kg/hm2,soybean 65 kg/hm2) and the without application of phosphorus(PO). in Renshou. Lezhi. Yaan. in order to provided the theoretical basis for optimizing the maize-soybean relay intercropping systems and it's fertilization management.The main results of the study were as followed(the data of below were the average of three places):1. The LER of maize-soybean relay intercropping systems were 1.66(P) and 1.94(P0). both bigger than 1. which showed advantages of maize-soybean relay intercropping systems. One of the advantages in which the treatment with non of phosphorus was significantly higher than that with P fertilization.Under the application of phosphorus(P). compared with two kinds of monoculture.the yield of maize and soybean of M/S were reduced 6.3%.28%:under the without application of phosphorus (P0). compared with two kinds of monoculture.the yield of maize and soybean of M/S were reduced -1.2%,9.3%. Compared with the PO.the yield of maize of M/S and M were increased 8.2%,17.3% under the application of phosphorus(P):the yield of soybean of M/S and S were increased 19.1%. 35.9% under the application of phosphorus(P). Dry matter accumulation showed the same trend as yield.2. Under the application of phosphorus(P) conditions, compared with two kinds of monoculture.the C accumulation of maize and soybean under M/S were reduced 4.3%, 24.8%; under the without application of phosphorus(PO). compared with two kinds of monoculture.the C accumulation of maize and soybean under M/S were reduced -4.2%, 3.8%. Compared with the P0. the maize's C accumulation of M/S and M were increased 9.7%,20.7% under the application of phosphorus(P); the soybean's C accumulation of M/S and S were increased 18.6%,36.5% under the application of phosphorus(P). Compared with two kinds of monoculture, the nutrient accumulation(including N,P,K) of maize and soybean tended to decrease, the difference of nutrient accumulation in maize was no significant, and soybean showed significant difference under M/S. The nutrient accumulation of maize and soybean was reduced under P0, the reduction extent of M/S is lower than two kinds of monoculture.3. The N,P,K were all in surplus under maize-soybean relay intercropping systems(M/S); the N and K were in deficit condition, but P was surplus under the relay-intercropped maize(M); the K was in deficit condition, but N and P were in surplus under the relay-intercropped soybean(S).4. Compared with the non application of phosphorus(PO), soil organic matter of M/S, M, S, were increased 3.01%,4.00% and 14.67% under the application of phosphorus(P). Compared with M, soil organic matter of M/S was increased 11.50%(P),7.83%(P0); Compared with S, soil organic matter of M/S was increased -0.98%(P),7.55%(P0). Compared with two kinds of monoculture, the soil available nitrogen, available phosphorus and available potassium were all increased under the maize and soybean relay intercropping systems, at the same time, adding P fertilizer can increase the nutrient content of soil.5. The analysis of emergy was:M/S>S>M, and the macro economic value was M/S >M>S.The index of input and output of emergy, macro economic value, advantage of system production, system stability, the environmental loading rate were reduced under the without application of phosphorus fertilizer, and the index of emergy sustainable was increased. The environmental loading rate were less than three and the emergy sustainable index were between 1?10 of the three kinds of cultivation models. The output of emergy of soybean was higher than maize, and the environmental loading rate showed the opposite trend. The index of emergy output, macro economic value, total advantage of system production and system stability of M/S were higher than M and S, then, M/S was the best cultivation model from the economic value was summed up. In order to optimized the maize-soybean relay intercropping systems, we could through increase the planting density or area of soybean, and reduce the planting density or area of maize, reduce the input of phosphorus fertilizer, reduce the frequency and depth of farming. |
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