The Comparative Study On Growth Potential, Yield And Quality Of Relay Cropping Soybean In Different Ecological Regions

Relay cropping soybean are planted in hills and low mountains of Sichuan and Chongqing and other places,vast territory and widely distribution. The production of relay cropping soybean are subjected to different weather conditions in different eco-regions.This test used" same year, multi-point and different sowing time"mode. The growth potential,yield and quality of relay cropping soybean in different ecological regions were compared. And the suitable sowing time of relay cropping soybean in different ecological were determined.We obtained the different climatic conditions by the means of different sowing time, and studied the influence of meteorological factors on soybean production.The meteorological basis of sowing time of relay cropping soybean was mastered in different ecological regions.The main results were shown follows:1. Germination and the relationship with meteorological factors.The lowest germination rate, longest germination time and cotyledon node were appeared in the Middle region of Sichuan(M-SC), followed by Southern region of Sichuan(S-SC), once again in Eastern of Sichuan(E-SC). The germination rate at June 3 sowing time was lower than others. Correlation analysis with meteorological factors showed that the TR, RH in d3, d4 after sowing significantly positively effected germination rate, the LT, RH in d5, d6 after sowing were positively significantly correlatd with cotyledon height; the negatively correlation between germination time and RH in d2,d3,d3 after sowing were significant. Seedling rate was consistent with germination rate, but the seedling rate was low because of bird pest in the later sowing time.2. Agronomic character and the relationship with meteorological factors.Leaf area, biomass, nod number and branch number reached maximum in E-SC, then in S-SC, and last in M-SC.The plant height with June 3 was lower when the branching initial, mainly due to limitations of TR and temperature; the plant height in early podding period were decreased with sowing date delayed, showed the positive relationships among the height and AT, SD and temperature. Leaf area and plant biomass decreased with the sowing date delayed (E-SC and M-SC), biomass in S-SC was first increased and then decreased with the delay of sowing date; TR, SD and temperature made the biomass and leaf area increased, the RH is too large to conduce to biomass and leaf area increasing. Branch number were decreasd with sowing date delayed, the RH limited the increasing the number of node and branch, but the AT, TR, SD were promoting, particularly the majority meteorological factors in S-SC were favorable to the nod number.3.The yield and the relationship with meteorological factors. The yield in different regions was:S-SC>E-SC>M-SC, the yield was decreased with delayed sowing in M-SC and E-SC, the yield was first increased and then decreased in S-SC, and there was greater decline with later sowing time. Suitable sowing time was form May 20 to June 10, and the sowing time at May 27 in S-SC, May 20 in M-SC and E-SC could obtained highest yield respectively. Correlation analysis with meteorological factors showed that the more TR, SD and TR significantly positively effected the yield increasing in the whole period of soybean growth, vegetative growth, reproductive growth stage (including the flower-pod stage and pod maturity);but LT and greater RH were disadvantageous to the yield formed. The correlation of the yield with biomass that in pod period and mature period was positively significant or highly significant.4.The yield compotent and the relationship with meteorological factors. The pods number of different regions were as follows:E-SC> S-SC> M-SC, first increased and then decreased with the sowing date postponed; seed numbers of per pod were as follows:E-SC> S-SC> M-SC, the trend of different regions inconsistent with the sowing date; 100-seed weights were as follows:S-SC>E-SC> M-SC, the trend of different regions inconsistent with the sowing date. Correlation analysis with meteorological factors showed that the pod number were significantly positively related to the AT, HT, SD, TR and RT in S-SC and M-SC; seed number per pod was negatively correlated with the HT, TR in S-SC; the 100-seed weights were significantly positively correlated with SD and RT, but significantly negatively related to LT and RH.5. The biological yield of different regions:E-SC> M-SC> S-SC, biological yield was first rised and then decreased in M-SC and S-SC, and gradually decreased in N-SC with delayed sowing. The AT, SD positively effected on biological yield; there was different effect for TR at different growth stage, TR was a negative impact on biological production at vegetative growth phase, but it was promoted at reproduction stage in M-SC. The SD and HT in E-SC was a negative impact on biological yield at in flowering-poding phase but was positive in the seed filling stage.6. The economic coefficient of different regional as:S-SC> E-SC> M-SC, economic coefficient were inconsistent with the trend of sowing date in different regions:it was increased with the delay of sowing time in M-SC and E-SC, while the economic coefficient was decreased with the delay of sowing date in S-SC.7. The protein content of different regions was:E-SC> S-SC> M-SC, it was inconsistent with the trend of sowing date in different regions. Through the correlation analysis with meteorological factors of different growth stages in different regions, protein content in M-SC was significantly positively correlated with the AT, SD and RT that was in the whole growth period, vegetative growth, reproductive growth stage; and also was significantly positively correlated with temperature during reproductive stage (pod-filling period), but it was significantly negatived with RH in the pod-filling period. The yield of protein was consistent with the seed yield performance that following the regions and sowing time changed.8. The fat content of different region:M-SC> S-SC>E-SC, it was increased with the sowing date delayed. Through the correlation analysis with meteorological factors of different growth stages in different regions, in M-SC it was significantly or highly significantly positively correlated with RH during the whole growth period, vegetative and pod-filling maturity; in S-SC it was significantly positively correlated with RH during the whole growth period, vegetative period; in E-SC it was not significantly correlated with meteorological factors. The fat content was negatively correlated with the temperature in any regions. The yield of fat was consistent with the seed yield performance that following the regions and sowing time changed.