Ameliorating acidity of an extensively‐managed permanent pasture soil     

《Soil Use and Management》2018,34(3):343-353

Acid soil amelioration was measured annually over an 11 year experiment. Lime, and superphosphate were surface‐applied under combinations of three rates of lime, viz. nil, lime to raise pH_{C a} of 0–10 cm to 5.0 (low rate) and 5.5 (high rate) respectively, two rates of superphosphate (125 kg/ha every 2 to 3 yr, 250 kg/ha/yr) and two sheep stocking rates. Soils were sampled at 0–2.5, 2.5–5, 5–7.5, 7.5–10, 10–15 and 15–20 cm. Soil pH stratification developed after lime application. By 11 yr lime had not raised pH_{C a} to either 5.0 or 5.5 in the 5–10 cm profile. However, pH_{C a} >5.0 or >5.5 were observed in the 0–5 cm profile. Under high P, low lime application, soil pH_{C a} was higher in the 0–2.5 cm profile at low stocking rate. Effects of applied lime on pH_{C a} declined with time and depth under low lime and the relationship with Al_ex which increased as pH_{C a} declined, was modelled. A rarely reported relationship showed that as soil C increased the apparent solubility of Al decreased. At the lowest pH_{C a} considered, there was a strong negative association between Al_ex and total C, becoming weaker with positive pH_{C a} increments. Higher P rates increased pH_{C a} under low lime contrasting with lesser effects on pH_{C a} under low P at the same lime rate. Slow and limited lime movement means that farmers growing acid sensitive plants must apply lime early enough and at rates and frequencies sufficient to ensure downward movement.  相似文献   

饲粮酸度与仔猪增重关系初探     

陈斌  刘孝憞 《中国畜牧杂志》1995,(6)

本研究以柠檬酸和延胡索酸作为酸化剂，对饲粮酸度与仔猪增重关系进行了初步研究。３５５头２９±１至５９±１日龄的大约克夏和长白仔猪分４次进行饲养试验。结果表明添加有机酸后饲粮的ｐＨ值下降，随添加剂量的加大，饲粮ｐＨ值呈近似直线下降；酸化饲粮的ｐＨ值在一定范围内增重效果较好；基础饲粮的ｐＨ值越大，酸化后ｐＨ值下降越多，适量酸化时提高增重的效果越明显。建议酸化饲粮时要测定基础饲粮酸化前后的ｐＨ值，以此作为适量酸化的依据。  相似文献   

Alleviation of soil acidity improves the performance of oil palm progenies planted on an acid Ultisol     

Jose A. Cristancho  Syed R. Syed Omar  Mohamed Y. Rafii 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(6):487-498

Abstract

Soil acidity is one of the main factors that limit profitable and sustained agricultural production. Oil palm (Elaeis guineensis Jacq.) is mainly planted in acidic soils. In the last years, there has been a stagnated yield and increases in disease incidence and severity worldwide that could be attributed in some extent to soil acidity. This study was conducted to determine the effects of soil acidity alleviation on oil palm seedlings. The effects of ground magnesium limestone or dolomite and magnesium carbonate (0, 1.1, 2.2, 3.3 and 4.4 t ha^?1) applied to an Ultisol dominated by kaolinite (pH in water 4.4) were evaluated on selected morphological, physiological and nutritional characteristics of hybrid (Deli dura × AVROS pisifera) and clonal (clone 366) oil palm progenies under nursery conditions for 8 months. Increasing rates of ground magnesium limestone and magnesium carbonate showed a significant effect on improving soil pH and lowering exchangeable aluminium. The hybrid oil palm showed significant either linear or quadratic trends for most of the parameters evaluated, indicating that the best responses for morphological and physiological traits were achieved from 2.5 to 4.23 t ha^?1 with ground magnesium limestone and 2.87 to 3.45 t ha^?1 with magnesium carbonate. Positive effects of increasing rates of ground magnesium limestone and magnesium carbonate were observed on nitrogen and magnesium uptake. Aluminium concentration in the third frond decreased significantly with increasing ground magnesium limestone rate. A significant reduction of manganese uptake was also observed with increasing rates of both ameliorants. The clonal oil palm progeny exhibited a better performance on un-amended treatment. This may be explained by the significant higher root growth of this progeny. Soil acidity alleviation improved the oil palm seedling growth. These results are important for the oil palm industry and could be applied in the nursery stage as well as extended to the immature stage.  相似文献   

酸沉降胁迫对不同家系马尾松幼苗耐酸性的影响     

王水良  王平  许建华 《林业科学》2013,49(7)

由于我国工业化、城镇化进程日益加快,环境污染不断加剧,由此引起酸雨频率及强度增加,长期酸雨侵蚀造成我国大面积土壤酸化.酸沉降影响森林的生长,主要表现:1)抑制植物养分、水分的吸收和运输;2)抑制光合作用;3)抑制呼吸作用;4)抑制其他代谢.这些抑制作用最终导致植物的萎黄、褪色、枯死(单运峰,1993;Zhu et al.,2008;李振华等,201 1).马尾松(Pinus massoniana)是我国南方主要造林树种和重要的工业用材树种,适应性强、生长快(丁贵杰等,2006;周政贤,2001),分布遍及南方15个省(区),分布区内地理环境存在极大差异.在长期的自然选择和生殖隔离下,马尾松存在着丰富的种内遗传变异,特别是对南方酸性土壤环境表现出很强的适应能力(Zeng et al.,2011).  相似文献   

Nutrient concentration and yield variation within southern soybean germplasm grown on acid Norfolk soil     

《Communications in Soil Science and Plant Analysis》2012,43(5):335-350

Abstract

Seventy‐one soybean genotypes were grown in the field on an acid Norfolk loamy sand to evaluate growth, seed yield, and nutrient concentrations in aerial plant fractions. The pH values in the Ap, A2, and B horizons were 4.6, 4.4, and 4.4, respectively. Cation exchange capacities (CEC) were 2.1, 0.9, and 2.8 me/100 g with an Al saturation of 34, 49, and 40%, respectively. Very few visual toxicity or deficiency symptoms were found among the genotypes. Analyses of aerial plant fractions collected when the genotypes were in bloom or early pod fill showed some significant differences, but In general P, K, Ca, and Mg concentrations were adequate, while Al, Fe, Mn, and Zn concentrations were very high. Average yields of genotypes in maturity groups IV, V, VI, VII, and VIII were 2.7, 2.7, 2.6, 2.4, and 2.2 t/ha, respectively. There were significant differences in seed yield among genotypes in maturity groups IV and VIII, but differences among genotypes in the other maturity groups were nonsignificant. Correlations between yield and nutrient concentration showed some significant relationships, but in general, this technique did not differentiate genotypes according to their tolerance to acid soil conditions.  相似文献   

Chemistry of soil aluminum     

《Communications in Soil Science and Plant Analysis》2012,43(7):619-636

Abstract

Better understanding of soil aluminum has had dramatic effects on the interpretation of many aspects of soil chemistry. Aluminum is a Group III element, metallic in nature, and exhibits both ionic and cuvaient bonding. It is the most plentiful of all metallic cations of the earth's crust. It is released from octahedral coordination with oxygen in minerals by weathering processes. Once released, the trivalent Al ion assumes octahedral coordination with six OH₂ groups each of which dissociates a H ion in sequence as pH increases. The resulting hydroxy‐Al ions are absorbed to the cation exchange capacity of the soil. Here they polymerize on charged surfaces and in the interlayers of the clay minerals obstructing both the contraction of the clay lattice and the exchange of cations. Soluble Al is toxic to most plants, and reacts readily with soluble phosphates converting them to relatively insoluble and plant‐unavailable forms. Adsorbed and polymerized aluminum affects actual lime requirements of soils by its acidic nature and indicated lime requirements by its effect on the buffers of the lime requirement test. The level of exchangeable Al has been suggested as an Index of lime requirement of acid soils, but this may be an adequate Index for liming only on highly weathered soils.  相似文献   

散放牧场泌乳初期低酸度酒精阳性乳患牛乳及血液学指标分析     

薛俊欣  徐莹莹  张瑞华  张铮臻  张克春 《中国奶牛》2012,(23):32-36

以分娩4周内的137头荷斯坦牛为试验动物,筛选19头酒精检测阳性且CMT检测阴性的牛只作为试验组,14头酒精检测和CMT检测均呈阴性的牛只为对照组,进行乳汁理化指标、血细胞、血液生化指标的检测。结果表明,低酸度酒精阳性乳在泌乳初期的发病率为42.34%,多发于泌乳天数低的奶牛,与隐性乳房炎无相关性,可引起乳脂率升高、乳糖率降低;试验组奶牛血液血红蛋白、白细胞、淋巴细胞、中间细胞升高,中性粒细胞降低,血清总蛋白、球蛋白、钙、镁、葡萄糖和胆固醇降低,血清钠、β-羟丁酸升高。  相似文献   

Site preparation,fertilization, and 10-year yields of hybrid poplar on a clearcut forest site in eastern Maine,USA     

M. M. Czapowskyj  L. O. Safford 《New Forests》1993,7(4):331-344

Cuttings of two similar hybrid poplar clones were planted on a drum-chopped, chip-harvested clearcut in eastern Maine. The site had never been previously cleared for agriculture. The coarse loamy glacial till soils were acid (pH < 5.0) and moist—moderately well—to somewhat poorly drained. Control, lime (L), L nitrogen (N), L phosphorus (P), LNP, and LNP potassium (K) treatments were established. Competing woody vegetation was mowed once per year for the first three years on half the area. Each mowed treatment produced significantly greater hybrid poplar biomass than the corresponding unmowed treatment. After 10 years, the mowed+LNPK treatment attained the greatest total biomass, 45 Mgha^-1, while the unmowed control attained the least, 2 Mgha^-1. On mowed plots, L produced 4 times the biomass of control: 32 vs 8 Mgha^-1. Unmowed plots with L and N produced about as much hybrid poplar biomass as the mowed control (8 Mgha^-1). Mowing and L each improved survival as well as growth.Deceased  相似文献   

清西陵地区土壤养分和酸碱状况的研究     

李惠卓  王文全 《河北林果研究》1996,(Z1)

为研究清西陵地区土壤养分和酸碱状况，对不同地形及不同母质母岩上发育的典型土壤剖面分层采集土样，进行室内分析。结果表明：中山、低山石灰性母质土壤呈微酸性，有机、无机养分丰富。丘陵区石灰性母质土壤呈微碱性，非石灰性母质土壤呈中性偏酸，土壤养分总体水平偏低，但不同剖面存在一定差异。  相似文献   

低盐高酸酱腌菜中亚硝酸含量的比较研究     

刘娜丽  杨红  韩晓静  李久长 《农产品加工．学刊》2012,(10):131-132,142

为探讨酱腌菜中亚硝酸盐含量与食盐、酸度等的关系,以丕蓝、白菜、芹菜、甘蓝、豆角等为原料,按不同比例食盐量、醋酸量、腌制温度制成酱腌菜,采用盐酸萘乙二胺分光光度法测定酱腌莱中亚硝酸盐含量。结果显示食盐质量分数为0.51%,酸度为1.18%的新醋腌制的丕篮亚硝酸盐含量最低;食盐质量分数11.61%,酸度为0.03%的酱咸菜亚硝酸盐含量最高。  相似文献