| Two super-high-yield soybean cultivars Liaodou14, Zhonghuang35, and one common cultivar Liaodou11were used in the pot experiment to investigate the effects of different diammonium phosphate(DAP) levels, plant density and population types(single seeding and mixed seeding) on soybean photosynthetic characteristic, nutrition accumulation, root character and yield in2012and2013. This trial intended to provide theoretical basis for soybean super-high-yielding cultivation. The main results showed as follows:1Effect of DAP on photo-physiology of super-high-yield soybeanLeaf greenness and photosynthetic rate of super-high-yielding cultivar were higher than those of common cultivar from flowering stage to seed filling stage, and the decreasing ranges of these traits were small. Leaf greenness and photosynthetic rate of super-high-yielding cultivar were showed an increasing tendency with the increment of DAP levels and plant density, while common cultivar kept higher photosynthetic rate under Omg/kg level and3plants/pot treatment. The differences of leaf greenness and photosynthetic rate between soybean cultivars were more obviously at mixed seeding.Under different DAP and plant density treatments, the diurnal variation photosynthesis of super-high-yield cultivar did not appear "noontime snooze" at seed filling stage. Photosynthesis of two cultivars were increased with diammonium phosphate level and plant density added. Overall, the photosynthesis of super-high-yield cultivar was higher than that of common cultivar after10o’clock and the difference was obviously under200mg/kg and9plants/pot treatments, especially at mixed seeding.Light response curves of super-high-yield cultivar were increased with diammonium phosphate level enhanced, but not common cultivar. In another hand, the light response curves of two cultivars both decreased with plant density added. Photosynthetic rate of super-high-yielding cultivar was higher than that of common cultivar when light intensity was above200μmol m-2s-1, and the difference was higher under200mg/kg and6plants/pot treatments,2Effect of DAP on nutrient uptake of super-high-yield soybeanThe content of N was relatively high in pod wall and seed of super-high-yield cultivar but decreased in vegetable organs under fertilization treatment. The content of P of super-high-yield cultivar was raised with diammonium phosphate level enhanced, especially the P content of pod wall and seed at200mg/kg level. However, the P content of root and stem of common cultivar was declined with fertilizing amount added. The content of K of two cultivars was decreased with diammonium phosphate level enhanced, except pod wall of super-high-yield cultivar. Generally the K content of super-high-yield cultivar was higher than that of common cultivar, and the difference was increased with fertilizing amount added, especially single seeding.On condition that plant density increased, the seed N content of super-high-yield cultivar was increased, but P content and K content of two cultivars was declined. Generally the N, P and K content of super-high-yield cultivar was higher than that of common cultivar, especially under6plants/pot treatment.N accumulation in every part of super-high-yield cultivar was increased with diammonium phosphate level increased, especially under200mg/kg treatment, while the N accumulation of common cultivar was decreased in that condition. With the fertilizing amount enhanced, P accumulation in every part of super-high-yield cultivar was increased except stem, as well as leaf and seed of common cultivar. K accumulation of stem, leaf, pod wall and seed of super-high-yield cultivar was increased with diammonium phosphate level enhanced, but not the common cultivar. In the case of adding fertilizing amount, the N, P and K accumulation of super-high-yield cultivar was higher than that of common cultivar, and the difference between two cultivars grew with diammonium phosphate level enhanced, especially under single seeding treatment. On condition that plant density increased, the N, P and K accumulation in every part of two cultivars was decreased, particularly the common cultivar. The N, P and K accumulation of super-high-yield cultivar was higher than that of common cultivar under6plants/pot and9plants/pot treatments, and the difference between two cultivars was larger at9plants/pot treatment.There existed a obviously effect of diammonium phosphate on N, P use efficiency (NUE, PUE) and N, P harvest index (NHI, PHI) of two soybean cultivars, but smaller on K use efficiency (KUE) and K harvest index (KHI). Generally, the N, P, K use efficiency and N, P, K harvest index of super-high-yield cultivar was higher than that of common cultivar, while the difference was larger at200mg/kg and mixed seeding treatments.Under different plant density, the nutrient use efficiency and nutrient harvest index were higher than those of common cultivar, while the difference was increased with plant density increased, especially at9plants/pot and mixed seeding treatments.3Effect of DAP on root character of super-high-yield soybeanThe root length, root surface, root volume and root dry weight of super-high-yield cultivar was increased with fertilization treatment, but the result was opposite of common cultivar. On condition that fertilizing amount increased, the root morphology character of super-high-yield cultivar was well, especially at200mg/kg and mixed seeding treatments.The root morphology character and root dry weight of two cultivars were declined with plant density decreased, and the root morphology character of super-high-yield cultivar was higher than those of common cultivar under6plants/pot and9plants/pot treatments, especially at mixed seeding.The root vigor and root bleeding of super-high-yield cultivar at mixed seeding treatment was enhanced with fertilizing amount increased, but not the bleeding of common cultivar. On condition that fertilizing amount increased, the root vigor and root bleeding of super-high-yield cultivar were well, and the difference between two cultivars was larger at highest fertilization level.The root vigor and root bleeding of two cultivars were declined with plant density decreased. Generally, the root vigor and root bleeding of super-high-yield cultivar was higher than those of common cultivar under different plant density, and the difference was increased with plant density increased, particularly at mixed seeding.Bleeding components of super-high-yield cultivar at seed-filling stage were higher than those of common cultivar under abundant fertilizing amount. At blooming stage, the bleeding components of super-high-yield cultivar were higher under6plants/pot treatment, and there was no difference between two cultivars at seed-filling stage.4Effect of DAP on agronomic traits and yield of super-high-yield soybeanPlant height and height of lowest pod of super-high-yield cultivar were shorter than those of common cultivar, while the stem diameter and pod number per plant of super-high-yield cultivar were more. Fertilization treatment promoted the height, stem diameter and pod number per plant of two cultivars, especially super-high-yield cultivar. The stem diameter and pod number per plant of soybean was decreased with plant density declined, and the decline range of common cultivar was larger.With fertilizing amount and plant density increased, the seed-stem ratio and economic coefficient of super-high-yield cultivar were higher than those of common cultivar, while the difference of seed-stem ratio between two cultivars was increased with plant density increased. Compared with check, the seed-stem ratio and economic coefficient of super-high-yield cultivar were larger, but not the common cultivar.Under contrast, seed yield of common cultivar was higher, however with fertilizing amount and plant density increased, seed yield of super-high-yield cultivar was significant higher than that of common cultivar, and the difference was increased with fertilization level and plant density increased. |
PDF Full Text Request