RESUMEN
Field trails were carried to study the effects of tobacco straw incorporation and potassium (K) fertilizer on rice yield, K uptake and use efficiency, and its substitute for K fertilizer under different paddy soil K levels in tobacco-rice rotation areas. Results showed that both tobacco straw incorporation (2250 kg·hm-2) and K fertilizer application (75 kg K2O ·hm-2) could increase grain yield and aboveground K uptake of rice. The treatment of tobacco straw incorporation with K fertilizer (St+NPK) got the best effect on rice yield compared with the control (NP). In this treatment (St+NPK), rice yields were increased by 13.3%, 17.1% and 13.5% for low-K soil (available potassium content < 100 mg·kg-1), middle-K soil (available potassium content 100-150 mg·kg-1) and high-K soil (available potassium content > 150 mg·kg-1), respectively, compared with NP. Tobacco straw incorporation (St+NP) could increase K fertilizer recovery efficiency and K fertilizer agronomic efficiency. Under the current practice of applying 75 kg K2O·hm-2, St+NPK showed no significant effect on K fertilizer recovery efficiency and K fertilizer agronomic efficiency, demonstrating that the recommended rate of K fertilizer might be more than the actual demand of rice growth. More importantly, data of tobacco straw substitute for K fertilizer showed that tobacco straw incorporation could replace 10%-22% K fertilizer during rice growing season, i.e. K fertilizer could be reduced by 7.2-16.5 kg·hm-2 for rice under the condition of tobacco straw incorporation. Therefore, it was suggested that straw incorporation could reduce the rate of K fertilizer for high-K soil, but the current K fertilizer inputs (75 kg K2O·hm-2) should be supplied to get high rice yield and maintain the soil potassium balance for low-K soil and middle-K soil.
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Fertilizantes , Nicotiana , Oryza/fisiología , Potasio/química , Agricultura , Suelo/químicaRESUMEN
A field micro-plot experiment was conducted to determine the effect of different placement methods and types of phosphorus (P) fertilizer on winter wheat growth and phosphorus uptake. P fertilizer types included monocalcium phosphate (MCP) and diammonium phosphate (DAP). P fertilizer application methods included: 1) surface broadcasting (S); 2) banding 5 cm below seeds (B0); 3) banding 5 cm below and 3 cm away from seeds (B3); 4) banding 5 cm below and 10 cm away from seeds (B10); 5) mixing with the 20% of the top soil below seeds (M). The result showed that B0 had the best effect on increasing yield, reached 7.63 t·hm-2 in MCP-B0 and 7.99 t·hm-2 in DAP-B0, which increased 10.3% and 10.7%, respectively compared with surface broadcasting. B10 had the lowest grain yield (6.60-6.77 t·hm-2). The total P uptake by wheat in B0 and M was at a relatively high level (34.42-35.60 kg·hm-2), B10 performed worst at all growth stages of wheat, while P uptake of DAP-B10 was 11.9% higher than MCP-B10. These results indicated that concentrating P fertilizer in a short distance near the seeds was an optimized application method for winter wheat in this region, and DAP performed better than MCP on P uptake and utilization of wheat under far banding.
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Agricultura/métodos , Fertilizantes , Fósforo/metabolismo , Triticum/crecimiento & desarrollo , Triticum/metabolismo , Fosfatos de Calcio , Grano Comestible/crecimiento & desarrollo , Grano Comestible/metabolismo , Fosfatos , Semillas , SueloRESUMEN
The acrylate-like materials were used to develop the polymer coated controlled release fertilizer, the nutrients release profiles were determined, meanwhile the Fourier transform mid-infrared photoacoustic spectra of the coatings were recorded and characterized; GRNN model was used to predict the nutrients release profiles using the principal components of the mid-infrared photoacoustic spectra as input. Results showed that the GRNN model could fast and effectively predict the nutrient release profiles, and the predicted calibration coefficients were more than 0.93; on the whole, the prediction errors (RMSE) were influenced by the profiling depth of the spectra, the average prediction error was 10.28%, and the spectra from the surface depth resulted in a lowest prediction error with 7.14%. Therefore, coupled with GRNN modeling, Fourier transform mid-infrared photoacoustic spectroscopy can be used as an alternative new technique in the fast and accurate prediction of nutrient release from polymer coated fertilizer.
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Fertilizantes , Espectroscopía Infrarroja por Transformada de Fourier , Acrilatos , Análisis de Fourier , Nitrógeno , Fósforo , Polímeros , Espectrofotometría Infrarroja , Análisis EspectralRESUMEN
Infrared photoacoustic spectroscopy (PAS) is a new style to obtain data based on photoacoustic theory. Photoacoustic thoeory is based on the absorption of electromagnetic radiation by analyte molecules, and the absorbed energy is measured by detecting pressure fluctuations in the form of sound waves or shock pulses. In contrast to conventional absorption spectroscopy, PAS allows the determination of absorption coefficients over several orders of magnitude, even in very black and strongly scattering soil samples. Red soil, fulvic soil and paddy soil were collected from Fengqiu National Ecological Experimental Station, Yingtan Red Soil Experimental Station, and Changshu Ecological Experimental Station, respectively. These soil samples were used as experimental materials to characterize the Fourier transform mid-infrared photoacoustic spectra (FTIR-PAS). Compared with infrared transmittance spectra and reflectance spectra, the testing of FTIR-PAS spectra was very fast and convenient without any pr-treatment, and there were more abundant absorptions as well as appropriate absorption values in the spectra; The main soil components (kaolin, bentonite, sand and CaCO3) also showed several strong absorptions with specific characteristics in the spectra; Further more, the interference of water with the PAS spectra was significantly smaller than that with reflectance spectra. Therefore, the soil properties could be better characterized by FTIR-PAS. The principal components analysis based on the FTIR-PAS spectra indicated that there were two main principal components (PCA1, PCA2) which contained 98.17% variance of the spectra, and the two-dimensionol distribution was made by plotting these two principal components to classify the soil type, and the results indicated that this distribution could be applied to distinguish soil type, which provided new technique for soil identification as well as further quantitative analysis in soil science.
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Espectroscopía Infrarroja por Transformada de Fourier/métodos , Análisis de Componente Principal , Radiación , Suelo/análisisRESUMEN
Surface water and shallow groundwater within the flow of an electroplating factory was analyzed in order to study the resulting impact. The analysis method of ICP-AES was used to analyze content of zinc, manganese, chromium, copper and nickel in surface water and groundwater samples. The results indicate acidic pollutants of zinc, manganese, chromium, copper and nickel were discharged from the factory with concentrations of 1.34, 3.77, 28.1, 6.40 and 9.37 mg x L(-1), respectively; and pH was 2.32. They all exceeded permissible levels according to Integrated Wastewater Discharge Standard except zinc. Factory discharge is responsible for the longitudinal distribution characteristics of heavy metals in the stream water downstream from the factory. Heavy metals variations in the well water do not suggest they were affected by heavy metals in the stream, indicating that the migration rates of heavy metals in soils were relatively low. Risk assessment shows surface water quality significantly deteriorated. Nickel and manganese in the stream water exceeded the standard levels seriously, and chromium and copper in some samples were also above Grade III standard levels according to Environmental Quality Standard for Surface Water. Moreover, all studied heavy metals in 14 groundwater samples measured within drinking water standard, except manganese in 4 groundwater samples, which were Grade IV according to Quality Standard for Ground water.
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Galvanoplastia , Residuos Industriales/análisis , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis , China , Medición de RiesgoRESUMEN
Determination the bioavailability of contaminants in different fertilizer management soils can be of great theoretical significance for predicting and decreasing the effect of pollutants on eco-environment. In this study, three different fertilization soils were employed in a 16-year field experiment: no fertilization (CK), composted wheat straw and oil cakes (OM) and NPK fertilizer (NPK). The influences of Cu2+ (100 mg/kg), Cd2+ (5 mg/kg) and cypermethrin (l0 mg/kg) and their combinations on microbial functional diversity were observed in different fertilization soils. The results showed that the highest microbial functional diversity was observed in the NPK treatment, followed by CK, and the lowest in the OM soil. At 72 h incubation, AWCD (average well color development) of the NPK soil was 1.19 times than that of the CK soil and 1.62 times than that of the OM soil. After addition of contaminants into soils, microbial functional diversity decreased to a different extent. The greatest decrease extent was recorded in the NPK soil, followed by CK and the least in OM. Combination of Cd and cypermethrin had the biggest influence on the microbial functional diversity. AWCD was decreased by 48%, six substrate groups and microbial diversity indices inhibited significantly in this treatment of the NPK soil. Although cypermethrin had little effect on soil microbial utilization of carbon source,utilization potential decreased greatly in combination pollution treatments, especially in combination with Cd2+. The effect of Cu2+, Cd2+ and cypermethrin and their combinations on soil microbes not only affected by the soil organic matter content, likely also by the constitution of organic matter and microbial community.
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Cadmio/toxicidad , Cobre/toxicidad , Piretrinas/toxicidad , Microbiología del Suelo , Contaminantes del Suelo/toxicidad , Biodiversidad , Monitoreo del Ambiente/métodos , FertilizantesRESUMEN
In this article, influence of monocalcium phosphate and potassium chloride application on nitrogen leaching in paddy soil of Taihu region was studied by soil column leaching. The results showed that nitrate nitrogen was the main component of nitrogen leaching without urea application which accounts for 93.39 percent of total nitrogen leaching (including urea, ammonium, and nitrate nitrogen). Amounts of urea, ammonium, and nitrate nitrogen in leachates increased significantly after urea application which account for 3.95, 15.25, and 80.80 percent of total nitrogen leaching respectively and for 0.26, 0.80, and 2.54 percent of applied nitrogen respectively. Amounts of urea, ammonium, and nitrate nitrogen in leachates were enhanced prominently by monocalcium phosphate or potassium chloride which are 4.54, 24.11, 71.34, and 3.45, 24.53, 72.02 percent of total nitrogen leaching respectively, and which are 0.39, 1.86, 3.34, and 0.32, 2.12, 4.06 percent of applied nitrogen separately. There is interactive influence on nitrogen leaching after application of monocalcium phosphate and potassium chloride together, and amounts of urea, ammonium, and nitrate nitrogen were 4.10, 27.35, and 68.55 percent of total nitrogen leaching, and 0.42, 2.60, and 4.26 percent of total applied nitrogen respectively. The leaching order of different form nitrogen followed as urea N > ammonium N > nitrate N, and leaching amounts of different form nitrogen followed as urea N < ammonium N < nitrate N.