ADSORPTION OF HERBICIDE-DERIVED p-CHLOROANILINE RESIDUES IN SOILS: A PREDICTIVE EQUATION

Relationships between the adsorption of p-chloroaniline and the original adsorbate concentration were investigated for five soils ranging in organic matter content from 1.7 to 8.1 per cent and in clay content from 0.5 to 21 per cent. Adsorption data were analyzed applying the linear form of the Freundlich equation. To evaluate the general relationship between adsorption of p-chloroaniline by soils and the solution concentration (C₀), values of partition coefficient (Kp), reflecting the magnitude of distribution of chemical at equilibrium between soil colloids and solution were calculated. The experiments showed that the regression parameters were significantly correlated with the soil organic matter content. A comparison of the experimental results obtained with other soils and the calculated values gave satisfactory agreement.     

南非Borakalalo国家公园二斑沙鸡(Pterocles bicinctus)的迁移(英文)

本文旨在描述可能引起南非Borakalalo国家公园内二斑沙鸡(Pterocles bicinctus)迁移行为的内在(繁殖)及外在因素(降雨量及植被情况)。该公园位于西北省比勒陀利亚以北80km,Jericho以北30km处。2010年,采取乘车辆沿固定路线穿越该保护区的方式搜集数据。车速为每小时10km,固定路线长为32km,调查强度为每月2天。二斑沙鸡平均每群2.47个个体。种群内雄性与雌性的比例为1:0.87。该鸟常出现在路边、遭踩踏过的矮草丛中或经焚烧但长出新叶的金合欢丛中。二斑沙鸡在该保护区主要出现在两个相对干燥的季节,即2–3月及7–9月。早晨在该公园的腹地能更多地观察到该鸟,而下午晚些时候,在Klipvoor河坝的水体边则可多见该鸟。讨论了可能影响二斑沙鸡迁移的5个因素,包括年降雨量、雨季中短时雨量大小、2–4km的日间饮水飞行、繁殖及草原植被情况。     

Liming reduces soil phosphorus availability but promotes yield and P uptake in a double rice cropping system

Liming is often applied to alleviate soil acidification and increase crop yield on acidic soils, but its effect on soil phosphorus (P) availability is unclear, particularly in rice paddies. The objective of this study was to examine the effect of liming on rice production, yield and P uptake in a three-year field experiment in a double rice cropping system in subtropical China. We also conducted an incubation experiment to investigate the direct effect of liming on soil available P and phosphatase activities on paddy soils in the absence of plants. In the incubation experiment, liming reduced soil P availability (measured as Olsen-extractable P) by 14–17% and inhibited the activity of soil acid phosphatase. Nonetheless, lime application increased grain yield, biomass, and P uptake in the field. Liming increased grain yield and P uptake more strongly for late rice (26 and 21%, respectively) than for early rice (15 and 8%, respectively). Liming reduced the concentration of soil available P in the field as well, reflecting the increase in rice P uptake and the direct negative effect of liming on soil P availability. Taken together, these results suggest that by stimulating rice growth, liming can overcome direct negative effects on soil P availability and increase plant P uptake in this acidic paddy soil where P is not the limiting factor.     

Potential use of Artemia biomass by‐products from Artemia cyst production for the nursing of goby Pseudapocryptes elongatus in Vietnam: effects on growth and feed utilization

The present study was performed to evaluate the effect of using Artemia biomass, by‐product from Artemia cyst production on growth and feed utilization of goby Pseudapocryptes elongatus fingerlings. A control diet containing fishmeal as main protein source was compared with four experimental diets in which fishmeal protein was replaced by increasing dietary levels of Artemia protein, namely 25%, 50%, 75% and 100%. The five test diets were compared with a commercial diet and dried Artemia. All diets were formulated to be equivalent in crude protein (360–370 g kg^?1) and lipid (58–65 g kg^?1). The experiment was conducted in 80 L plastic tanks filled with water at a salinity of 15 g L^?1. Goby fingerlings with 0.21 g initial weight were fed the test diets for 30 days. The results showed that weight gain and specific growth rate of goby were positively correlated with total feed intake. Moreover, growth performances and feed utilization in the fry receiving the commercial feed and fishmeal control diet were similar, both were inferior to the groups fed dried Artemia and the based formulated diets. These results illustrate that both dried Artemia and Artemia‐based feeds can be used for feeding goby fingerlings, indicating the high potential of using locally produced Artemia biomass, which could contribute to reduce the reliance on fishmeal and improve profits for Artemia producers.     

比较土壤和土壤－植物系统中由尿素转化的N2O的排放

A pot experiment with a sandy loam soil and spring wheat as test crop was conducted to compared the N2O emissio from soil system with plant cut off and from soil-plant syste with plant kept.The results showed that after urea fertilizer applied,the N2O emission from soil and soil-wheat system decreased exponentially with time,and its total amount was 0.34-0.63% and 0.33%-0.58% of applied urea-N respectively,no significant difference being found between these two systems.The N2O emission urea-N respectively,no significant difference being found between these two systems.The N2O emission had a very significant negative relationship (P=0.01) with the biomass of wheat plant.A combined application of urease inhibitor hydroquinone and nitrification inhibitor dicyandiamide could reduce the N2O emission by 50%-83% and 46-74%,respectively,from soil and soil-wheat system.The N2O was mainly produced and emitted from soil,and the soil biochemical regulation.i.e.applying related inhibitors into soil could effectively diminish the urea derived N2O emission.     

The Solar Acoustic Spectrum and Eigenmode Parameters

The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure.