预防为主 强化监督 依法防治水土流失

预防为主强化监督依法防治水土流失王文学（山西省人民政府，太原６３００７２）山西地处黄土高原，山多、坡陡、沟深，水土流失严重，土壤贫瘠，生产条件差。全省１１１个农业县（市、区）中有５０个属贫困县，水土流失严重制约和影响了农业及整个经济建设的发展，是造成...     

Quality of liming materials used in aquaculture in Thailand

Samples of 45 brands of liming materials were obtained in Thailand and analyzed for chemical and physical properties. Eight of 10 products sold as ground calcium carbonate (calcitic agricultural limestone) were properly identified by vendors and of high quality, that is, neutralizing value and fineness rating above 85%. Seven of 15 products sold as ground dolomite (dolomitic agricultural limestone) were properly identified, seven were ordinary pulverized limestone instead of dolomite, and one was lime. The seven dolomitic agricultural limestone samples were of high quality, that is, fineness ratings above 85% and neutralizing values above 95%. Only two of eight misidentified samples were of high quality. Only one of four products sold as marl had neutralizing value and efficiency rating above 85%, but all were properly identified. Five products sold as crushed seashell had been burned and should have been identified as lime. However, neutralizing values (72–103%) were lower than those of good quality lime. All 13 samples sold as lime were properly identified, and eight were of good quality, that is, neutralizing value above 120% and fineness rating above 85%. The cost of liming materials ranged from US$ 0.01 to 0.20kg^–1 for marl and from US$ 0.10 to 0.14kg^–1 for lime. There was no relationship between product quality and cost. Fish and shrimp farmers in Thailand should insist that manufacturers and vendors of liming materials provide data on product composition.     

Influence of bone meal degelatinisation and calcium source and particle size on broiler performance,bone characteristics and digestive and plasma alkaline phosphatase activity

1. The current experiment was performed to elucidate the effects of degelatinised bone meal (DBM) in combination with different particle sizes of limestone or oyster shell on broiler performance, bone characteristics and digestive and plasma alkaline phosphatase (ALP) activity.

2. Treatments were applied as a 3 × 3 factorial arrangement with three sources of P (DCP, bone meal and DBM) and three particle sizes (50, 100 and 200 µm) of limestone. Chickens were given either DCP or DBM with oyster shell (523 µm), resulting in a total of 11 treatments with 5 replicates of 8 chicks.

3. Performance criteria were measured weekly. Tibia strength, ash, calcium (Ca) and phosphorus (P) content and plasma P and Ca concentration along with plasma and intestinal alkaline phosphatase (ALP) activity and P digestibility were measured on d 14 and 28.

4. Body weight and FCR were improved in chicks which were fed DBM or oyster shell in comparison to the DCP and limestone respectively (P ≤ 0.05). Performance was influenced (P ≤ 0.05) by particle size; with coarser particles BW and feed intake were increased (P ≤ 0.05). Tibia shear force and P content were reduced (P ≤ 0.001), whereas tibia shear energy, length, ash and Ca content were increased by substitution of DCP with DBM or bone meal (P ≤ 0.001; P ≤ 0.05). A significant difference was observed in the tibia length between the chicks fed oyster shell or limestone with different particles (P ≤ 0.05). Plasma P concentration was reduced in chicks were fed with DBM, bone meal and lower limestone particle size. Intestinal ALP activity was increased (P ≤ 0.001) in chicks which were fed DBM, bone meal, oyster shell or coarse particles of limestone. The P digestibility in chicks fed bone meal was lower than that of those fed DBM or DCP (P ≤ 0.01). Overall, gelatin removal from bone meal improved broiler bone characteristics through the P digestibility and intestinal ALP activity enhancement.     

西南乌江流域石灰岩风化过程中锰和磷的迁移富集

如何提高石灰土中锰和磷矿质养分的植物利用效率,已成为喀斯特地区面临的重要问题。选取乌江流域9条石灰岩风化剖面,运用R型聚类分析和质量平衡法,研究了石灰岩风化过程中锰和磷迁移富集行为。结果表明,区内石灰土中锰和磷的富集程度远高于上陆壳、桂林石灰土和世界土壤。土壤中锰的富集是钙等易溶元素迁出以及锰从剖面上部淋滤到下部并沉淀的结果。磷在石灰土中的富集主要是钙等更易溶组分迁出的结果。研究区石灰土相对于桂林石灰土具有低pH值特征,相对于桂林石灰土、世界土壤和上陆壳具有低盐基度特征,其富集的锰和磷具有一定的迁移活性。图4表1参23     

石灰性土壤桑树黄化病的成因及防治对策

通过对石灰性土壤地区的桑园调查和室内化验分析,结果表明,石灰性土壤桑树黄化病主要是缺铁引起的,由于土壤有效铁含量较低（DTPA—Fe≤13mg／kg）,或是因土壤中交换性Ca和HCO3^-浓度过高,使土壤铁的有效性降低,桑树表现缺铁症状。通过合理施肥、种植铁高效基因型的桑树品种和改善土壤通气条件,可以有效地防治桑树黄化病。     

石灰岩山区工程建设对水土流失的影响研究

从对影响石炭岩山区土壤侵蚀的因素分析入手,获取有关可蚀性因子信息,利用变径流系数经验公式和通用水土流失方程（USLE）对住宅工程建设前后的建设期间的地表径流损失量和土壤流失量进行计算和预测,最后总结工程开发建设对石灰岩山区水土流失的影响特点。     

徐州石灰岩山地风景林营建的主要技术

石灰岩山地是一类具有特殊生态特征的立地类型。徐州地区石灰岩荒山生态风景林建设在全国具有较高的影响。通过系统地总结徐州地区石灰岩山地风景林营建的规划设计,立地分类与造林整地,树种配置与栽植以及主要森林植被类型———侧柏林分的生长、自然演替、森林抚育和人工促进侧柏林演替的主要技术,为同类地区山地风景林营建提供参考。     

人工降雨条件下不同粒径泥沙中氮磷流失特征分析

针对香溪河流域农业面源污染严重以及坡耕地传统耕作模式造成的氮磷流失等问题,选取库区典型石灰性土壤进行人工模拟降雨试验,研究地表径流和不同粒径泥沙中氮磷等养分流失特征。结果表明:地表径流中不同形态氮素养分的流失过程,均表现为降雨初期出现浓度峰值,之后随降雨的进行迅速降低,TP输出浓度先有一个较小幅度的下降过程,之后随产流时间的延长而增加,最后趋于稳定;流失泥沙颗粒组成表现为粘粒(2μm)与细砂粒(20~200μm)含量随降雨过程进行有一定增加,而粉粒(2~20μm)和石砾(2000μm)含量却有所降低,粗砂粒(200~2 000μm)含量则几乎不变;不同粒径径流泥沙中各养分流失浓度最大的均为粒径2μm粘粒,粒径200μm的颗粒各养分流失贡献率均高达70%以上,表明水土流失导致土壤中大量细小颗粒与养分流失,其中流失泥沙携带的养分含量与细小颗粒含量呈明显的正相关。     

Upper Profile Changes Over Time in an Appalachian Hayfield Soil Amended with Coal Combustion By‐products

Abstract

Large amounts of flue gas desulfurization (FGD) and fluidized bed combustion (FBC) by‐products from burning coal, consisting primarily of gypsum, are available for potential use as a soil amendment. However, information is limited on longer‐term changes in chemical and physical properties induced over time and over small depth increments of the upper soil profile after applying these amendments. This study examined longer‐term effects in an abandoned Appalachian pasture soil amended with various liming materials and coal combustion by‐products (CCBPs). Soil chemical and physical properties were investigated over time and depths. The results indicated limited dissolution and movement of the calcium (Ca) and magnesium (Mg) applied with the chemical amendments, except for Ca and Mg associated with sulfate. However, sufficient dissolution occurred to cause significant increases in exchangeable Ca and Mg and decreases in exchangeable Al that were reflected in corresponding increases in soil pH. These beneficial effects persisted over time and were confined to the upper 0‐ to 15‐cm depth of the profile. The greatest benefits appeared to be in the upper 0‐ to 5‐cm surface layer. Both Ca and Mg applied as calcitic dolomitic limestone tended to be immobilized in the upper 0‐ to 5‐cm layer of the soil profile; Ca more so than Mg. The presence of S applied in the FGD and FBC amendments appeared to enhance the mobility of Ca and Mg. The ratio of Ca/Mg in HCI extracts from the calcitic dolomitic treatment was close to that of applied calcitic dolomite, implying that the inactive component in soil might be the original calcitic dolomite particles. Soil physical properties measured over small depth increments showed that application of the amendments improved the saturated hydraulic conductivity only in the upper 0‐ to 5‐cm depth and had little or no significant effect on the dry bulk density and plant‐available water.     

Soil Fertility Amendments and White Grub Populations of Turf

Liming materials, calcium carbonate versus calcium magnesium silicate, were compared for effects on native white grub (Coleoptera: Scarabaeidae) populations in a New Jersey lawn. A silt loam soil near Princeton, N.J., of mixed cool-season turf with an initial pH of 5.0 received applications of either liming material in January 2007 for a target pH of 6.5. Control plots received no lime application. Grub numbers were reduced by more than 50% in plots amended with either calcium magnesium silicate or calcium carbonate when compared with the controls. Both calcium magnesium silicate and calcium carbonate were similarly effective in achieving this benefit.