Overestimation of nitrogen（N） uptake requirement is one of the driving forces of the overuse of N fertilization and the low efficiency of N use in China. In this study, we collected data from 1 844 site-years of ric...Overestimation of nitrogen（N） uptake requirement is one of the driving forces of the overuse of N fertilization and the low efficiency of N use in China. In this study, we collected data from 1 844 site-years of rice（Oryza sativa L.） under various rotation cropping systems across the Yangtze River Valley. Selected treatments included without（N0 treatment） and with N application（N treatment） which were recommended by local technicians, with a wide grain range of 1.5–11.9 t ha–1. Across the 1 844 site-years, over 96% of the sites showed yield increase（relative yield〉105%） with N fertilization, and the increase rates decreased from 78.9 to 16.2% within the lowest range 〈4.0 to the highest 〉6.5 t ha–1. To produce one ton of grain, the rice absorbed approximately 17.8 kg N in the N0 treatment and 20.4 kg N in the N treatment. The value of partial factor productivity by N（PFP N） reached a range of 35.2–51.4 kg grain kg–1 with N application under the current recommended N rate. Averaged recovery rate of N（RE N） was above 36.0% in yields below 6.0 t ha–1 and lower than 31.7% in those above 6.0 t ha–1. Soil properties only affected yield increments within low rice yield levels（〈5.5 t ha–1）. There is a poor relationship between N application rates and indigenous nitrogen supply（INS）. From these observations and considering the local INS, we concluded there was a great potential for improvement in regional grain yield and N efficiency.展开更多
Direct-sowing establishment method has great significance in improving winter oilseed rape（Brassica napus L.） production and guaranteeing edible oil security in China. However, nutrient responses on direct sown wint...Direct-sowing establishment method has great significance in improving winter oilseed rape（Brassica napus L.） production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape（DOR） performance and population development dynamic are still not well understood. Therefore, five on-farm experiments were conducted in the reaches of the Yangtze River（RYR） to determine the effects of nitrogen（N）, phosphorus（P）, and potassium（K） deficiencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment（NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1） and three nutrient deficiency treatments based on the NPK treatment, i.e., –N, –P, and –K. The results indicated that DOR population density declined gradually throughout the growing season, especially at over-wintering and pod-development stages. Nutrient deficiency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deficiency treatment. Averaged across all the experiments, seed yield reduced 61% by N deficiency, 38.3% by P deficiency, and 14.4% by K deficiency. The negative effects of nutrient deficiency on DOR performances followed the order of –N–P–K, and the effects were various among different nutrient deficiencies. Although N deficiency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deficiency significantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deficiency mainly decreased individual growth and yield, but did not affect density dynamic. Our results highlighted the importance of balanced NPK application in DOR production, suggesting that management strategy of these nutrients should be comprehensively considered with an aim to build an appropriate population structure with balanced plant density and individual growth.展开更多
A field experiment was conducted to study the effects of boron (B), molybdenum (Mo), zinc (Zn) and their interactions on seed yield and yield formation of rapeseed (Brassica napus L. var. Huashuang 4). Application of ...A field experiment was conducted to study the effects of boron (B), molybdenum (Mo), zinc (Zn) and their interactions on seed yield and yield formation of rapeseed (Brassica napus L. var. Huashuang 4). Application of B fertilizer to a sandy soil increased the seed yield by 46.1% compared to the control and also created a considerably higher seed yield than the two treatments solely applying Mo and Zn fertilizers, which suggested that B was a main constraint for the seed yield of Huashuang 4 in this experiment. The effect of B fertilizer on the seed yield was attributed to an increase in the number of seeds per silique and siliques per plant. The combined application of B with Mo or Zn resulted in higher seed yield than the application of B, Mo or Zn alone, and the seed yield of the B+Mo+Zn treatment was the highest in all treatments, 68.1% above the control. Dry matter accumulation of seed followed a typical S-shaped curve and it was higher in plants supplied with B than in plants without B. A small but significant increase in the seed oil content and an improvement in the oil quality were also observed in all treatments compared with the control. These results suggested that optimal micronutrient application could provide both yield and quality advantages for rapeseed in poor soil.展开更多
To study the mechanism of plant K use efficiency, both K high and low use efficiency cotton genotypes, 103 and 122, respectively, were selected from 86 cotton cultivars （Gossypium hirsutum L.）. The research was cond...To study the mechanism of plant K use efficiency, both K high and low use efficiency cotton genotypes, 103 and 122, respectively, were selected from 86 cotton cultivars （Gossypium hirsutum L.）. The research was conducted using pot experiment for planting cotton on without K （0.0 g kg-1 soil） and with K （0.4 g kg-1 soil） treatments in 2005. Experimental result showed that, with K deficiency stress, genotype 103 grew much better than genotype 122 except that its lower leaves showed the symptoms of K deficiency, whereas all the leaves of genotype 122 showed the symptoms of K deficiency. Root dry matter weights of treatments for genotype 103 with and without K application were 1.07 and 1.25 times of genotype 122. It indicated that the root system of genotype 103 was well developed and has better nutrition uptake capability than that of genotype 122. The result also showed that the cotton shoots of genotype 103 were 1.07 and 1.13 times over genotype 122 on treatments of with and without K application. It indicated that genotype 103 has stronger transport organs. In genotype 103, plants, dry matter, and potassium were mainly transported to cotton bolls. The boll dry weight of genotype 103 was 2.58 times in without K treatment and 1.90 times in with K treatment over genotype 122. The potassium accumulation in bolls of genotype 122 was only 49.3% of that in genotype 103. Potassium accumulation in the other organs of genotype 103 was relatively low compared with in bolls. This indicated that the distribution of K and organic matter in genotype 103 was more efficient than genotype 122. The main differences between high K efficiency cotton genotype 103 and low K efficiency genotype 122 lie in their potassium nutrition and organic matter using efficiency on uptake, transportation, accumulation, distribution, and utilization.展开更多
HG103,a high K-efficiency cotton cultivar with high-yield potential,and LG122,a low K-efficiency cotton cultivar with low-yield potential were used to study the genotypic variation on yield,economic responses,and soil...HG103,a high K-efficiency cotton cultivar with high-yield potential,and LG122,a low K-efficiency cotton cultivar with low-yield potential were used to study the genotypic variation on yield,economic responses,and soil indigenous K exploitation for cotton in pot and field conditions in 2006 and 2007.Results indicated that both the cultivars differed significantly in the rate of translocation of dry matter into reproductive organs and the time of running into reproductive stage.Cotton yield and economic parameters of HG103 were much better than LG122.Potassium content in cotton shells reached the highest level at maturity stage for both genotypes.Results also showed that the K content in each plant part of HG103 was lower than that of LG122.The two genotypes showed different efficiencies and abilities on absorbing soil rapidly available K and slowly available K.LG122 showed higher absorption of K rate than HG103 after K fertilization,but on the contrary,HG103 uptake more soil indigenous K than LG122 in no K fertilization treatment.This result indicated that HG103 could tolerant and absorb more soil indigenous K than LG122,under condition of soil K stress.LG122 could grow well and absorb more K nutrient when soil K supply is sufficient.Our results demonstrated that higher K content in plant tissues and higher K uptake by plant may not an exclusive condition for high yield planting with K fertilization.Earlier translocation of more dry matters into reproductive organs is one of the key mechanisms of high K use efficiency in cotton.展开更多
基金the Special Fund for Agro-Scientific Research in the Public Interest in China (201103039)the Fundamental Research Funds for the Central Universities Key Projects, China (2013PY113)+1 种基金the Natural Science Foundation of Hubei Province, China (2013CFB203)the Research Funds of Huazhong Agricultural University, China (52209814032) for providing financial support
文摘Overestimation of nitrogen（N） uptake requirement is one of the driving forces of the overuse of N fertilization and the low efficiency of N use in China. In this study, we collected data from 1 844 site-years of rice（Oryza sativa L.） under various rotation cropping systems across the Yangtze River Valley. Selected treatments included without（N0 treatment） and with N application（N treatment） which were recommended by local technicians, with a wide grain range of 1.5–11.9 t ha–1. Across the 1 844 site-years, over 96% of the sites showed yield increase（relative yield〉105%） with N fertilization, and the increase rates decreased from 78.9 to 16.2% within the lowest range 〈4.0 to the highest 〉6.5 t ha–1. To produce one ton of grain, the rice absorbed approximately 17.8 kg N in the N0 treatment and 20.4 kg N in the N treatment. The value of partial factor productivity by N（PFP N） reached a range of 35.2–51.4 kg grain kg–1 with N application under the current recommended N rate. Averaged recovery rate of N（RE N） was above 36.0% in yields below 6.0 t ha–1 and lower than 31.7% in those above 6.0 t ha–1. Soil properties only affected yield increments within low rice yield levels（〈5.5 t ha–1）. There is a poor relationship between N application rates and indigenous nitrogen supply（INS）. From these observations and considering the local INS, we concluded there was a great potential for improvement in regional grain yield and N efficiency.
基金supported by the National Key Technologies R&D Program of China during the 11th Five-Year Plan period (2010BAD01B05)the Earmarked Fund for China Agriculture Research System (CARS-13)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University of China (IRT1247)the Fundamental Research Funds for the Central Universities,China (2013PY113)
文摘Direct-sowing establishment method has great significance in improving winter oilseed rape（Brassica napus L.） production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape（DOR） performance and population development dynamic are still not well understood. Therefore, five on-farm experiments were conducted in the reaches of the Yangtze River（RYR） to determine the effects of nitrogen（N）, phosphorus（P）, and potassium（K） deficiencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment（NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1） and three nutrient deficiency treatments based on the NPK treatment, i.e., –N, –P, and –K. The results indicated that DOR population density declined gradually throughout the growing season, especially at over-wintering and pod-development stages. Nutrient deficiency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deficiency treatment. Averaged across all the experiments, seed yield reduced 61% by N deficiency, 38.3% by P deficiency, and 14.4% by K deficiency. The negative effects of nutrient deficiency on DOR performances followed the order of –N–P–K, and the effects were various among different nutrient deficiencies. Although N deficiency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deficiency significantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deficiency mainly decreased individual growth and yield, but did not affect density dynamic. Our results highlighted the importance of balanced NPK application in DOR production, suggesting that management strategy of these nutrients should be comprehensively considered with an aim to build an appropriate population structure with balanced plant density and individual growth.
基金supported by the Program for New Century Excellent Talents in University, China (No.NCET-05-0666)the Ministry of Science and Technology of China (No.2006BAD25B01).
文摘A field experiment was conducted to study the effects of boron (B), molybdenum (Mo), zinc (Zn) and their interactions on seed yield and yield formation of rapeseed (Brassica napus L. var. Huashuang 4). Application of B fertilizer to a sandy soil increased the seed yield by 46.1% compared to the control and also created a considerably higher seed yield than the two treatments solely applying Mo and Zn fertilizers, which suggested that B was a main constraint for the seed yield of Huashuang 4 in this experiment. The effect of B fertilizer on the seed yield was attributed to an increase in the number of seeds per silique and siliques per plant. The combined application of B with Mo or Zn resulted in higher seed yield than the application of B, Mo or Zn alone, and the seed yield of the B+Mo+Zn treatment was the highest in all treatments, 68.1% above the control. Dry matter accumulation of seed followed a typical S-shaped curve and it was higher in plants supplied with B than in plants without B. A small but significant increase in the seed oil content and an improvement in the oil quality were also observed in all treatments compared with the control. These results suggested that optimal micronutrient application could provide both yield and quality advantages for rapeseed in poor soil.
文摘To study the mechanism of plant K use efficiency, both K high and low use efficiency cotton genotypes, 103 and 122, respectively, were selected from 86 cotton cultivars （Gossypium hirsutum L.）. The research was conducted using pot experiment for planting cotton on without K （0.0 g kg-1 soil） and with K （0.4 g kg-1 soil） treatments in 2005. Experimental result showed that, with K deficiency stress, genotype 103 grew much better than genotype 122 except that its lower leaves showed the symptoms of K deficiency, whereas all the leaves of genotype 122 showed the symptoms of K deficiency. Root dry matter weights of treatments for genotype 103 with and without K application were 1.07 and 1.25 times of genotype 122. It indicated that the root system of genotype 103 was well developed and has better nutrition uptake capability than that of genotype 122. The result also showed that the cotton shoots of genotype 103 were 1.07 and 1.13 times over genotype 122 on treatments of with and without K application. It indicated that genotype 103 has stronger transport organs. In genotype 103, plants, dry matter, and potassium were mainly transported to cotton bolls. The boll dry weight of genotype 103 was 2.58 times in without K treatment and 1.90 times in with K treatment over genotype 122. The potassium accumulation in bolls of genotype 122 was only 49.3% of that in genotype 103. Potassium accumulation in the other organs of genotype 103 was relatively low compared with in bolls. This indicated that the distribution of K and organic matter in genotype 103 was more efficient than genotype 122. The main differences between high K efficiency cotton genotype 103 and low K efficiency genotype 122 lie in their potassium nutrition and organic matter using efficiency on uptake, transportation, accumulation, distribution, and utilization.
基金supported by the National Natural Science Foundation of China (40801112)the Knowledge Innovation Program of the Chinese Academy of Sciences (KSCX2-YW-N-002)the China Program of International Plant Nutrition Institute (IPNI-HB-37)
文摘HG103,a high K-efficiency cotton cultivar with high-yield potential,and LG122,a low K-efficiency cotton cultivar with low-yield potential were used to study the genotypic variation on yield,economic responses,and soil indigenous K exploitation for cotton in pot and field conditions in 2006 and 2007.Results indicated that both the cultivars differed significantly in the rate of translocation of dry matter into reproductive organs and the time of running into reproductive stage.Cotton yield and economic parameters of HG103 were much better than LG122.Potassium content in cotton shells reached the highest level at maturity stage for both genotypes.Results also showed that the K content in each plant part of HG103 was lower than that of LG122.The two genotypes showed different efficiencies and abilities on absorbing soil rapidly available K and slowly available K.LG122 showed higher absorption of K rate than HG103 after K fertilization,but on the contrary,HG103 uptake more soil indigenous K than LG122 in no K fertilization treatment.This result indicated that HG103 could tolerant and absorb more soil indigenous K than LG122,under condition of soil K stress.LG122 could grow well and absorb more K nutrient when soil K supply is sufficient.Our results demonstrated that higher K content in plant tissues and higher K uptake by plant may not an exclusive condition for high yield planting with K fertilization.Earlier translocation of more dry matters into reproductive organs is one of the key mechanisms of high K use efficiency in cotton.
