An evaluation of the Olsen test as a measure of plant-available phosphorus in grassland soils derived from basalt parent material     

A.A.W. Bell  J.S. Bailey  R.V. Smith 《Soil Use and Management》2005,21(3):322-329

Abstract. Anecdotal and circumstantial evidence have suggested that the Olsen test underestimates plant-available phosphorus (P) in basaltic soils in Northern Ireland. Therefore, the ability of this test to predict plant-available P in basaltic (and non-basaltic) soils was investigated by regressing Olsen-P data against herbage P indices calculated from plant tissue test data using the diagnosis and recommendation integrated system. The average Olsen-P concentration for a range of fields situated on basaltic soils was considerably lower than the average Olsen-P concentration for a range of fields situated on non-basaltic soils, and yet mean sward P status, as given by the herbage P indices, was similar for both groups of fields. Herbage P indices were also much better correlated with Olsen-P measurements in non-basaltic soils than in basaltic soils. Furthermore, at low Olsen-P values (≶9mgPL⁻¹) some swards on basaltic soils were genuinely deficient in P, while others were sufficient or even in surplus for this nutrient. The results confirm that Olsen-P is inadequate as a predictor of plant-available P in basaltic soils. It is concluded that an alternative soil test is needed to provide a reliable assessment of plant-available P in basaltic soils, to prevent overuse of fertilizer and manure P and to minimize the amounts of P entering local watercourses.  相似文献   

Evaluation of two N cycle models for the prediction of N mineralization from grassland soils in the UK     

A. Bhogal  A. Bhogal  M.A. Shepherd  D.J. Hatch  L. Brown  S.C. Jarvis 《Soil Use and Management》2001,17(3):163-172

Abstract. The ability of two nitrogen cycle models, of contrasting complexity, to predict N mineralization from a range of grassland soils in the UK, was evaluated. These were NCYCLE, a simple mass balance model of the N cycle in UK grasslands, and CENTURY, a more complex model simulating long-term C, N, P & S dynamics in grassland ecosystems. The models were tested using field measurements of net N mineralization from a range of grassland soils (differing in soil type, history & management practice), obtained over a 2 year period using a soil core incubation technique. This method was considered to measure the total net release of mineral N from the soil organic matter over a specified time, including N which may have been recycled several times. NCYCLE consistently under-estimated mineralization rates at all sites. By contrast, there was some correlation between CENTURY predictions of net N mineralization and field measurements. This may have reflected the different abilities of the two models to simulate N recycling. Neither model, however, was able to predict adequately the effect of cultivation and reseeding on net N mineralization.  相似文献   

The use of urban organic wastes in the control of erosion in a semiarid Mediterranean soil     

M. Ros  C. Garcia  T. Hernandez 《Soil Use and Management》2001,17(4):292-293

Abstract. A two year field experiment was carried out in a semiarid Mediterranean area in order to evaluate, the effect on soil erosion of adding different urban organic wastes: a stabilized municipal waste (compost), an unstabilized municipal waste, and an aerobic sewage sludge. All the treatments significantly reduced soil erosion, compared to the control soil. The soil amended with compost was the most effective treatment, reducing soil loss by 94% and runoff by 54%.  相似文献   

Effects of 'Agri-SC' soil conditioner on soil structure and erodibility: some further observations     

M.A. Fullen  A.M. Tye  K.E. Cookson 《Soil Use and Management》1995,11(4):183-185

Abstract. In field and laboratory experiments the conditioner‘Agri-SC’has shown improvements in the structure of loamy sand soils in east Shropshire, UK. It resulted in statistically significant decreases in soil bulk density values and increases in soil porosity and aggregate stability. Further experiments are in progress on both loamy sand and silt loam soils.  相似文献   

上虞海涂实验农场中心试验区排水系统探讨     

吴玉卫  施茂荣  严康良  王永土 《浙江大学学报(农业与生命科学版)》1996,(1)

上虞市海涂实验农场中心试验区的排水系统，能满足十年一遇的年最大２４ｈ降雨，两天内排出的要求。滨海盐土的地下水位高，农田基本建设除用浅、密的排水沟布置外，还应结合平整土地、发展灌溉以及适用的农、林技术等综合措施，才能达到治盐改土的效果。  相似文献   

西北干旱区生态环境建设支撑体系的构建   总被引：6，自引：2，他引：6  

钱鞠  王根绪  马金辉  高前兆 《干旱地区农业研究》2003,21(1):102-107,138

西北干旱区的自然环境脆弱性叠加不合理的水土资源开发等人类活动干扰是导致区域生态环境日趋恶化的根本原因,已严重制约社会经济的可持续发展。针对当前生态环境建设实际,提出应在实现水资源可持续利用、建立完善的管理体制及法律体系、调整产业结构、积极推进城镇化进程、大力发展科技教育等方面采取有力措施。以此为重要支撑,恢复与重建受损生态系统,改善区域生态环境,实现环境与经济社会协调发展。  相似文献   

樟子松在西北干旱沙区的光合日变化特征   总被引：7，自引：0，他引：7  

吴春荣  金红喜  严子柱  满多清  马全林  安富博 《干旱区资源与环境》2003,17(6):144-146

在甘肃省民勤治沙站 ,用 Li- 62 0 0便携式光合仪分别测定人工栽植的 4龄、9龄和 2 0龄樟子松的净光合速率日进程 ,其结果表明 :在干旱沙区 ,9龄以上樟子松的光合速率在午前随光强和气温而上升 ,午后下降。其 4龄、9龄和 2 0龄樟子松的最大净光合速率分别为 8.7μmol· m- 2 · s- 1、62 .3μmol· m- 2 · s- 1、1 9.7μmol· m- 2 · s- 1。  相似文献   

宁夏南部山区抗旱应灾农业技术体系的探讨     

王龙昌  马林  韩媛芬  贾志宽 《干旱地区农业研究》2003,21(4):121-125

通过分析宁夏南部山区干旱气候规律及其对农业的胁迫效应，指出干旱灾害是宁南农业生产力水平低而不稳的重要原因；加强与气候条件相适应的农业技术的研究和改进，是宁南农业持续稳定发展的重要基础。结合多年来的旱地农业科技攻关研究工作，在对单项农业技术进行组装集成的基础上，建立了包括工程措施、生物措施、农艺措施、化学措施等四大措施紧密结合的宁南山区抗旱应灾农业技术体系，探讨了宁南山区抗旱应灾的主要技术策略。对于广大旱农地区提高农业系统防旱抗旱能力，实现农业高产稳产具有普遍指导意义。  相似文献   

干旱区自然灾害监测预警系统的一般模式——以塔里木盆地为例     

王让会  卢新民 《干旱区资源与环境》2002,16(4):64-68

我国西部干旱区生态环境脆弱 ,自然灾害频繁。塔里木盆地是我国最大的内陆盆地 ,干旱、大风、沙尘暴、洪水、泥石流以及地震、雪灾等自然灾害 ,严重地影响到盆地的生态安全。在RS、GIS及 GPS等技术支持下 ,研究各自然灾害的孕灾机理及过程 ,建立自然灾害的监测评价及预警系统 ,对于塔里木盆地生态环境建设具有重要意义。  相似文献   

Black carbon estimation in French calcareous soils using chemo‐thermal oxidation method     

G. Caria  D. Arrouays  E. Dubromel  C. Jolivet  C. Ratié  M. Bernoux  B. G. Barthès  D. Brunet  C. Grinand 《Soil Use and Management》2011,27(3):333-339

We studied the black carbon (BC) content of ca. 405 samples from French topsoil and artificial soil and carbonate mixtures. Our protocol involved three main steps: (i) decarbonation by HCl, (ii) elimination of non‐pyrogenic organic carbon in a furnace at 375 °C, and (iii) quantification of residual carbon by CHN analysis. BC content increased for calcareous soils according to their carbonates content. Subsequent analyses confirmed the existence of a methodological artefact for BC determination only in calcareous soils. Decarbonation changes the thermal properties of organic matter, creating more recalcitrant carbon than in the initial sample. Higher CaCO₃ and organic carbon content results in a more pronounced artefact. The reversal of the first two steps of the chemo‐thermal oxidation method (i.e. thermal oxidation before soil decarbonation) eliminates this artefact. Overall, our results suggest that BC content may have been overestimated in a large number of studies on calcareous soils.  相似文献