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1.
ＩＮＴＲＯＤＵＣＴＩＯＮＺｈｅｊｉａｎｇＰｒｏｖｉｎｃｅｌｏｃａｔｅｄｉｎｓｏｕｔｈｅａｓｔｅｒｎＣｈｉｎａｂｅｌｏｎｇｓｔｏｔｈｅｓｕｂｔｒｏｐｉｃａｌｃｌｉｍａｔｉｃｚｏｎｅｗｉｔｈｗａｒｍｔｅｍｐｅｒａｔｕｒｅ (ｍｅａｎｔｅｍｐｅｒａｔｕｒｅ 1 5-1 8℃ )ａｎｄａｄｅｑｕａｔｅｒａｉｎｆａｌｌ (ａｎｎｕａｌｐｒｅｃｉｐｉｔａ ｔｉｏｎ 1 1 0 0 -1 90 0ｍｍ) .Ｏｆｔｈｅｔｏｔａｌｏｆ1 .62ｍｉｌ ｌｉｏｎｈａｃｕｌｔｉｖａｔｅｄｌａｎｄｉｎｔｈｉｓｐｒｏｖｉｎｃｅ ,1 .2 7ｍｉｌｌｉｏｎｈａａｒｅｒ…  相似文献   

2.
Field experiments were conducted in farmers’ rice fields in 2001 and 2002 to study the effects of nitrogen (N) management strategies on N use efficiency in recovery (RE), agronomy (AE) and physiology (PE) and redistribution of dry matter accumulation (DMA) and nitrogen accumulation (NA) in two typical rice cultivars in Jinhua, Zhejiang Province. This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency (NUE) of rice in Zhejiang by comparing farmers’ fertilizer practice (FFP) with advanced site-specific nutrient management (SSNM) and real-time N management (RTNM). The results showed that compared to FFP, SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering. There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution (post-DMR) and post-flowering nitrogen redistribution (post-NR). These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer’s routine practice of Zhejiang. With SSNM, about 15% of the current total N input in direct-seeding early rice and 45% in single rice could be reduced without yield loss in Zhejiang, China. Project supported by the International Rice Research Institute (IRRI), Swiss Agency for Development and Cooperation (SDC), the Potash & Phosphate Institute and the Potash & Phosphate Institute of Canada (PPI-PPIC), the International Fertilizer Industry Association (IFA), the International Potash Institute (IPI), and 948 Project of the Ministry of Agriculture of China (No. 2003-Z53)  相似文献   

3.
Potential growth of two widely-grown hybrid rice varieties in the Jinhua district of Zhejiang Province, Shanyou63 for mid-rice and Xieyou46 for late rice, was simulated using a crop growth model of WOFOST. Parameters of the rice growth in WOFOST were calibrated through field experiments from 1999 to 2002 in Jinhua. The potential yield simulated with WOFOST was about 12 t/ha for Shanyou63 and 10 t/ha for Xieyou46, which are in good agreement with the highest recorded yield obtained in this area. Under farmers practice, current yield is about 7.5 t/ha for Shanyou63 and 6.5 t/ha for Xieyou46. There is a gap between the actual rice yield and the potential yield for these two hybrid rice varieties grown in this area. The attainable target yields were set to 70% to 75% of their potential yields for the two varieties. A recently developed software ＂Nutrient Decision Support System （NuDSS）＂ for irrigated rice was used to optimize nutrient management for these two rice varieties. According to NuDSS, the optimal fertilizer N requirement for the target yields was about 150 kg/ha for Shanyou63 and about 120 kg/ha for Xieyou46, which were only about 70% of the fertilizer N application under current farmers＇ practice. Comparing with farmers＇ practice, there is great potential to increase actual rice yields and to reduce fertilizer N use rates by improving rice crop management practice in Jinhua.  相似文献   

4.
Studies were initiated for two consecutive years to find out the effect of time of transplanting and seedlings hill^-l on the productivity of rice in Dera Ismail Khan district of North West Frontier Province （NWFP）, Pakistan. The experiment was laid out in a randomized complete block design with split plot arrangements. Main plots consisted of four transplanting dates viz. 20th and 27th of June and 4th and 1 lth of July while sub-plots contained 1, 2, 3 or 4 seedlings hill^-1. Among transplanting dates, June 20th planted crop gave highest paddy yield and net return with I seedling hill^-1. It explains that the use of more seedlings hill^-1 not only adds to cost but is also a mere wastage of natural resources. Based on research findings, we conclude that the use of I seedling hill^-1 is most appropriate for timely sowing otherwise 4 seedlings hill^-1 should be used to compensate for the yield gap in late transplanted rice.  相似文献   

5.
Soil test crop response （STCR） correlation studies were carried out in Vindhyan alluvial plain during 2001 to 2004 taking IR-36 as test crop to quantify rice production in the context of the variability of soil properties and use of balanced fertilizers based on targeted yield concept. The soils were developed on gently sloping alluvial plain with different physiographic settings and notable variation in drainage condition. Soil properties show moderate variation in texture （loamy to clay）, organic carbon content （4.4 to 9.8 g/kg）, cation exchange capacity （10,2 to 22.4 cmol （p＋）/kg） and pH （5.3 to 6,4）, Soil fertility status for N is low to medium （224 to 348 kg/ha）, P is medium to high （87 to 320 kg/ha） and K ranges from medium to high （158 to 678 kg/ha）. Database regarding nutrient requirement in kg/t of grain produce （NR）, the percent contribution from the soil available nutrients [CS （%）] and the percent contribution from the applied fertilizer nutrients [CF （%）] were computed for calibrating and fbrmulating fertilizer recommendations. Validity of the yield target for 7 and 8 t/ha was tested in farmers＇ fields and yields targets varied at less than 10%. The percent achievement of targets aimed at different level was more than 90%, indicating soil test based fertilizer recommendation approach was economically viable within the agro-ecological zone with relatively uniform cropping practices and socio-economic conditions.  相似文献   

6.
在粮食生产系统中,影响粮食产量的因素有很多。根据2000~2009年安徽省粮食产量及相关指标,通过计算灰色关联度,得到影响粮食生产的相关因子的灰色关联系数由大到小依次为:化肥施用量、粮食播种面积、乡村从业人员、有效灌溉面积、农业机械总动力、农民人均纯收入,可见在选取的6个指标中,化肥施用量和粮食播种面积对粮食产量的影响最大,而农民人均纯收入对其影响较小。  相似文献   

7.
1IntroductionIn recent years,there are many papers published ontoluene oxidation to benzaldehyde.The most i mpor-tant research works of these papers are electric oxida-tion and toluene oxidizied by using air in gas phase orin liquid phase.A novel technology for benzaldehydeproduction is developed,with which manganese sul-fate reacts with ammonium carbonate to yield manga-nese carbonate and ammoniun sulfate.Manganese car-bonate is baked for being changed into manganese ses-quioxide,which can ox…  相似文献   

8.
46 inbred NIH mice were infected by chloroquine resistant strain of Plasmodium yoelii. The ultrastructure changes were observed under the administration of ketotifen(10mg·kg−1·d−1) and chloroquine(10mg·kg−1·d−1) combination and one after another respectively. The effect of taking ketotifen and chloroquine combination showed that parasites died rapidly with a few of intermittent membranes and vacuoles. The effect of taking two kinds of drugs one after another showed that there were exceedingly rich membranes, concentric arrangement structures similar to rough endo-reticulum and conspiciously blocking of the formation of food vacuoles.  相似文献   

9.
本文采用二因素随机区组试验,探讨了不同NPK养分,不同磁化处理的磁性化肥对杂交水稻产量及产量构成因素的影响。统计结果表明:不同磁肥对水稻产量的影响差异达到了极显著水平,其中以N_3P_1K_1×磁化粉煤灰(2000GS磁化处理)的磁肥的效果最好。养分与磁处理间存在显著互作反应,不同磁肥对有效穗数,每穗实粒数的影响均极显著,但对千粒重的影响不显著,水稻产量与有效穗数的偏相关程度较大,水稻产量约70％可由每株有效穗数、每穗实粒数的变异决定,NPK养分是磁肥主成分,其效应大于磁效应,且磁效应与养分有关。  相似文献   

10.
The micro-Raman method is a non-contact and non-destructive method for thermal conductivity measurement. To reduce the measurement error induced by the poor fit of the basic equation of the original micro-Raman method, we developed a new basic equation for the heat source ofa Gaussian laser beam. Based on the new basic equation, an analytical heat transfer model has been built to extend the original micro-Raman method to thin films with submicrometer- or nanometer-scale thickness. Experiments were performed to measure the thermal conductivity of dielectric thin films with submicrometer- or nanometer-scale thickness. The thermal resistance of the interface between dielectric thin films and their silicon substrate was also obtained. The obtained thermal conductivity of silicon dioxide film is 1.23 W/（m.K）, and the interface thermal resistance between silicon dioxide film and substrate is 2.35×10^-8 m^2.K/W. The thermal conductivity and interface thermal resistance of silicon nitride film are 1.07 W/（m.K） and 3.69×10^-8 m^2.K/W, respectively. The experimental results are consistent with reported data.  相似文献   

11.
The effects of salinity(50 mmol/L NaCl) and Cd(1 μmol/L CdCl2) as sole and combined on growth and photosyn-thetic parameters were studied using two soybean genotypes,Huachun 18 and NGB.The concentrations of Cd2 ,Zn2 ,Ca2 ,Mg2 ,K and Na were also determined in seeds and pods.Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate(Pn) in the treatments of salinity stress alone and combined stress(NaCl Cd),showing that it is relatively sensitive to salinity.The decrease in Pn caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency(the ratio of variable fluorescence to maximal fluorescence,Fv/Fm),whereas the decease in NGB was mainly related to reduced stomatal conductance(Gs).The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone.Greater change in the pod concentrations of Zn2 ,Ca2 ,Mg2 ,K and Na was detected under salt stress for Huachun 18 than for NGB.The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.  相似文献   

12.
A laboratory incubation experiment was conducted to study the effect of copper as cupric sulfate (CuSO4.5H2O), and lead as lead acetate (Pb (OAc)2) on the size of the microbial biomass in red soil. The metals were applied, separately at six different levels: Cu at 50, 100, 200, 300, 400, and 600 μg·g−1 soil and Pb at 100, 200, 400, 600, 800, and 1000 μg·g−1 soil. In comparison to uncontaminated soil, the microbial biomass carbon (Cmic) and biomass nitrogen (Nmic) decreased sharply in soils contaminated with Cu and Pb. The microbial biomass C:N ratio in the metal contaminated soil was observed to be considerably higher than that in untreated control. Between the two tested metals, Cu displayed greater biocidal effect on microbial biomass carbon and nitrogen than Pb, showing their relative toxicity in the order: Cu≫Pb. Project (No. 49671050) supported by National Natural Science Foundation of China. Wa’el Mohamad—Former Ph. D. Student of Zhejiang University and is working in Ministry Of Agriculture (P. O. box. 2099), Amman, Jordan.  相似文献   

13.
1, 10-Phenanthroline (phen) was tested as a complexing agent for on-line preconcentration of iron on RP-C18 material in a microcolumn with flow injection coupled with flame atomic absorption spectrometer (FI-FAAS). The on-line formed Fe(II)-phen complexes were adsorbed on the C18 sorbent material. Various parameters affecting the on-line Fe(II)-phen complex formation and its subsequent adsorption in the microcolumn as well as its elution into the nebulizer of AAS were optimized. A 2.5×10−3 mol/L phen in 2% through the microcolumn for 30 s. The adsorbed Fe(II)-phen complexes in the microcolumn were eluted with ethanol in 10 s into the nebulizer of AAS. Ascorbic acid (5×10−4 mol/L) was added to the sample solution for the reduction of Fe(III) to Fe(II). A good precision (RSD=1.1%,n=10), high enrichment factor (19) and sample throughput (90 h−1) with detection limit (3σ) of 3 μg/L were obtained. The method was applied on standard reference materials (i. e. mussel and tomato leaves,) for iron determination and yielded results agreeing well with certified values. Project supported by the Zhejiang Provincial Natural Science Foundation of China and Zhejiang Environmental Protection Foundation From Pakistan Institute of Nuclear Science & Technology, Islamabad, Pakistan and now ZJ University, Ph. D. student.  相似文献   

14.
Pakistani wheat varieties are grown over a wide agro-climatic range and as such are anticipated to exhibit yield and quality differences. It is therefore necessary to investigate the nutritional status of wheat varieties in terms of biochemical and physiochemical characteristics available for food and nutritional purposes in Pakistan. The result shows that wheat grains of different varieties contain a net protein level of 9.15%～10.27%, 2.15%～2.55% total fats, 1.72%～1.85% dietary fibers,77.65×10^-6～84.25×10^-6 of potassium and 7.70× 10 6～35.90× 10^-6 of sodium ions concentration, 0.24× 10^-6～0.84× 10^-6 of phosphorus, 1.44%～2.10% ash, 31.108～43.602 g of thousand grain mass （TGM） and 8.38%～9.67% moisture contents. This study is significant in providing an opportunity to explore the available wheat varieties and to further improve their nutritional excellence and also essential for setting nutritional regulations for domestic and export purposes.  相似文献   

15.
采用广义灰色关联矩阵优势分析方法对河南省1990-2012年间的粮食总产量和粮食单产及其影响因素进行了分析。结果表明：粮食总产量和粮食单产受各相关因素的综合影响基本一致,说明河南省粮食总产量的增产主要依靠粮食单产的提高;而农田有效灌溉面积、化肥施用量和农用机械总动力是提高粮食单产的主控因素,应发展有机化肥逐步形成农田生态系统的良性循环;同时应严格执行耕地保护政策,确保粮食播种面积。  相似文献   

16.
The effects of pH andEh on release of nitrogen and phosphorus from sediments of West Lake under different conditions were investigated by simulation test. Results showed that the net flux of NH4 +-N release from sediments increased with pH, but NO3 −-N showed negative-going release at all tested pH levels. The net flux of NH4 +-N release from sediments was higher under anaerobic or aerobic condition of the overlying water, but only under aerobic condition would net release of NO3 −-N occur. It was also shown that phosphorus released was mainly in its inorganic form, higher pH and anaerobic conditions of overlying water greatly stimulated release of phosphorus. In situ measurement at several West Lake locations indicated that sediment resuspension induced by boat propeller stimulated nutrients release from sediment into overlying water. Project (No.294059) supported by National Natural Science Foundation of Zhejiang Province, China  相似文献   

17.

Background

Nitrogen (N), phosphorous (P), and potassium (K) are critical nutrient elements necessary for crop plant growth and development. However, excessive inputs will lead to inefficient usage and cause excessive nutrient losses in the field environment, and also adversely affect the soil, water and air quality, human health, and biodiversity.

Methods

Field experiments were conducted to study the effects of controlled-release fertilizer (CRF) on seed yield, plant growth, nutrient uptake, and fertilizer usage efficiency for early ripening rapeseed (Xiangzayou 1613) in the red-yellow soil of southern China during 2011–2013. It was grown using a soluble fertilizer (SF) and the same amounts of CRF, such as SF1/CRF1 (3750 kg/hm2), SF2/CRF2 (3000 kg/hm2), SF3/CRF3 (2250 kg/hm2), SF4/CRF4 (1500 kg/hm2), SF5/CRF5 (750 kg/hm2), and also using no fertilizer (CK).

Results

CRF gave higher seed yields than SF in both seasons by 14.51%. CRF4 and SF3 in each group achieved maximum seed yield (2066.97 and 1844.50 kg/hm2, respectively), followed by CRF3 (1929.97 kg/hm2) and SF4 (1839.40 kg/hm2). There were no significant differences in seed yield among CK, SF1, and CRF1 (P>0.05). CRF4 had the highest profit (7126.4 CNY/hm2) and showed an increase of 12.37% in seed yield, and it decreased by 11.01% in unit fertilizer rate compared with SF4. The branch number, pod number, and dry matter weight compared with SF increased significantly under the fertilization of CRF (P<0.05). The pod number per plant was the major contributor to seed yield. On the other hand, the N, P, and K uptakes increased at first and then decreased with increasing the fertilizer rate at maturity, and the N, P, and K usage efficiency decreased with increasing the fertilizer rate. The N, P, and K uptakes and usage efficiencies of the CRF were significantly higher than those of SF (P<0.05). The N accumulation and N usage efficiency of CRF increased by an average of 13.66% and 9.74 percentage points, respectively, compared to SF. In conclusion, CRF significantly promoted the growth of rapeseed with using total N as the base fertilizer, by providing sufficient N in the later growth stages, and last by reducing the residual N in the soil and increasing the N accumulation and N usage efficiency.
  相似文献   

18.
Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T. Blake) plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap flux density (SFD) of Eucalyptus was closely related to daily atmospheric vapor pressure deficit (VPD) (R 2=0.76, P=0.01 at Hetou and R 2=0.7021, P=0.01 at Jijia) at both sites. No significant relationship existed between daily SFD and mean daily air temperature at both sites. Daily SFD varied with wind speed Y=−17585X 3+15147X 2−1250.7X+2278.4 (R 2=0.68; P=0.01) at Hetou and Y=−101.67X 3−1.65X 2−376.4X+1914.8 (R 2=0.40, P=0.05) at Jijia, where Y was daily SFD, X was daily wind speed. Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2 kPa, within which daily SFD varied from 540±70 L/(m2·d) to 4739±115 L/(m2·d) at Hetou site, from 397±26 L/(m2·d) to 3414±191 L/(m2·d) at Jijia site; (2) Diurnal SFDs at Hetou site were much higher under low relative humidity (<30%) and slightly lower under high relative humidity (>80%) compared with those at the Jijia site; (3) The upper and lower threshold of daily and diurnal RAD for the optimal water use of E. urophylla plantations were 18±2.7 and 2±1 MJ/(m2·d), 669 and 0 J/(cm2·h) during the observation period. Project supported by Knowledge Innovation Funds from Chinese Academy of Sciences (Nos. KSCX2-SW-120, KZCX1-SW-01-01A3) and the Key Project of Guangdong Natural Science Foundation (No. 010567), China  相似文献   

19.
Effects of dietary supplementation with fructooligosaccharides on the excretion of nitrogen and phosphorus inMiichthys miiuy fries were investigated. Nine hundredMiichthys miiuy fries were divided into 3 groups, each with triplicates. The basal diet and the basal diet supplemented with carnitine groups were considered as the negative and positive controls respectively. Results showed that the nitrogen concentration in excreted feces decreased significantly in fries fed the diet supplementation with 1000×10−6 fructooligosaccharides and 200×10−6 carnitine (P<0.05). The ammonic-nitrogen concentration decreased significantly in the carnitine group only (P<0.05), indicating the decreasing tendency caused by the supplementation with fructooligosaccharides. Supplementation with both did not have significant effects on the concentration of phosphorus in feces ofMiichthys miiuy fries. Project supported by Public Bidding Item in Key Research of Zhejiang Province (No. 02110281-2) and Ningbo Tackle Key Problem for Agricultural Development (No. 2004C-100030), China  相似文献   

20.
Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA). Methods: The amount of3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA) content of the VSMC were assayed. Results: 1×10−9, 1×10−8, 1×10−7 mol/L LPA in a concentration dependent manner, induced the amount of3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%, and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P<0.01) respectively in the amount of3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P<0.05), 29.6% (P<0.01), and 48.9% (P<0.01) respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P<0.01) respectively, in the 1×10−7 mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion. Project (No. 491010-W50339) supported by Chinese Traditional Medicine Administration Bureau of Zhejiang Province, China  相似文献   

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