甘薯淀粉白度的研究

用石灰水调整磨浆液ｐＨ值至７．５～８．５，（３０００－４０００ｒ／ｍｉｎ）离心分离和沉淀，能有效改善甘薯淀粉白度。     

施用石灰降低污染稻田上双季稻镉积累的效果

【目的】研究在不同镉（Cd）污染程度稻田上施用石灰（CaO）的效果以及双季稻稻米Cd积累的差异,为早、晚稻季下不同污染程度稻田上的稻米安全生产提供参考。【方法】在湖南省选取43个县（区）的典型Cd污染稻田作为试验点,以常规栽培作为对照,研究施用石灰（1 200 kg·hm^-2）后,轻度污染（土壤有效镉≤0.2 mg·kg^-1）、中度污染（0.2 mg·kg^-1土壤有效镉≤0.4 mg·kg^-1）、重度污染（0.4 mg·kg^-1土壤有效镉≤0.6 mg·kg^-1）和严重污染（土壤有效镉>0.6 mg·kg^-1）稻田土壤pH、土壤有效镉含量、稻米Cd含量以及稻米富集系数的变化。【结果】（1）从Cd污染稻田整体的角度分析,相比常规栽培,施用石灰能够极显著降低早、晚稻米Cd含量均值,降幅分别为31.0%和28.6%。（2）从不同稻季下不同污染程度稻田的角度分析,相比常规栽培,施用石灰能够降低早稻季中度、重度和严重污染稻田的稻米Cd含量均值,降幅分别为37.0%、38.7%（P＜0.05）和22.6%;施用石灰能够降低晚稻季轻度、中度、重度和严重污染稻田的稻米Cd含量均值,降幅分别为2.0%、31.3%（P＜0.05）、31.8%和22.9%。不同污染程度稻田施用石灰后能够提高土壤pH,降低土壤有效镉含量,使稻米Cd富集系数明显下降,实现对稻米Cd含量的调控。【结论】施用石灰能够有效调控早稻季的轻度、中度、重度以及晚稻季的轻度Cd污染稻田的稻米Cd含量均值,降至限量标准（0.2 mg·kg^-1）以下。因此,以石灰施用为基础,结合其他降Cd措施,实施“分稻季分污染程度”和“晚稻优先于早稻”的治理思路,能提高大田生产上稻米Cd含量调控的稳定性并降低治理成本。     

花生的低湿密闭储藏

为了解决花生过夏安全储藏问题,采用块状生石灰为吸湿剂,以"二合一小药袋"为缓释熏蒸剂,以五面密封为气调手段,进行了花生的低湿密闭储藏,以低湿为主导,使花生较长期处于低湿、低氧、低药的条件下,取得了安全过夏的良好效果.     

中国东南部红壤施用石灰和石膏后底土酸性的减缓

Application of lime or gypsum is a common agricultural practice to ameliorate soils with low pH which prohibits crop production. Its integrated effect on soil properties in a red soil derived from Quaternary red clay in Southeast China is discussed in this paper. Application of gypsum in the topsoil without leaching raised soil pH and promoted the production of soil NH₄, but lime addition had a contrary effect. Generally, application of lime and/or gypsum has little effect on soil electrical properties. Gypsum had a little effect on soil exchange complex and its effect went down to 30 cm in depth. The effect of lime reached only to 5 cm below its application layer. With leaching, Ca transferred from top soil to subsoil and decreased exchangeable Al in subsoil. Gypsum application led to a sharp decrease in soil exchangeable Mg but had no effect on K.     

石灰稳定土的常见病害及防治措施

根据石灰稳定土性质及特点 ,分析了石灰稳定土几种常见病害的形成机理及防治措施     

Effect of Deep Placement of Slow-release Fertilizer (Lime Nitrogen) Applied at Different Rates on Growth, N2 Fixation and Yield of Soya Bean (Glycine max [L.] Merr.)

A new fertilization method with deep placement of slow‐release N fertilizers, such as coated urea and lime nitrogen (LN) (calcium cyanamide) at 20 cm depth was found to promote soy bean seed yield. In the present study, the effect of deep placement of LN was investigated on different parameters such as growth, N accumulation, N₂ fixation activity and yield of soy bean by applying LN at different rates in the rotated paddy field of Niigata, Japan. In addition to the basal fertilizer, ammonium sulphate (16 kg N ha^?1), deep placement of LN was conducted by applying various amounts such as 50 kg N ha^?1 (A50), 100 kg N ha^?1 (A100) and 200 kg N ha^?1 (A200) at 20 cm depth in separate plots. A ¹⁵N‐labelled LN fertilizer was also employed for each of the above treatments to calculate N utilization from LN in separate plots. Soya bean plant growth and N₂ fixation activity were periodically analysed. Both plant growth and N accumulation were found to increase with LN treatment compared with control plants. An increase in N₂ fixation activity was found in the A100 plots. The total seed yield was the highest in the deep placement of LN with A100 (73 g per plant) compared with other treatments. The visual quality of harvested seeds also showed that A100 enhanced the quality of seeds compared with other treatments. Thus, it is suggested that N fertilization management with particular reference to optimum amount of fertilizers is important for maximum growth, N₂ fixation and enhancement of seed yield of soy bean.     

Soil tillage systems and forms of lime application on soil attribute enhancements in ratoon sugarcane

Combining deep tillage (DT) with lime application at greater depths may improve sugarcane yield. The objective of this study was to evaluate the impact of conventional tillage (CT) and DT systems and liming on sugarcane productivity and soil physical attributes. The experiment was conducted in a clayey-textured Rhodic Hapludox soil cultivated with sugarcane for two growing seasons (first and third ratoons) using a randomized block design with four treatments and four repetitions. The treatments consisted of DT without liming (DT0), DT with liming (DT2), CT without liming (CT0) and CT with liming (CT2). In addition to sugarcane stalk and sugar yields, macroporosity (MA), microporosity (MI), total soil porosity (TP), weighted average diameter (WAD), aggregate stability index (ASI), soil penetration resistance (SPR), pH, potential acidity (H + Al), total soil organic carbon (SOC), particulate organic carbon (POC), mineral-associated organic carbon (MOC), calcium (Ca) and magnesium (Mg) were analysed. DT2 promoted the best soil conservation effect on sugarcane. In general, DT, regardless of lime application, reduced SOC and POC in soil surface layer. Nevertheless, in the long term, localized lime addition resulted in significant reductions in compaction, reaching values below 2 MPa. The soil fertility improvement provided by DT2 promoted increased sucrose concentrations and stalks yield. Considering that there was an improvement in the physical quality and fertility of soil for better plant development, the deep tillage with localized lime addition can be considered an effective alternative for sugarcane cultivation.     

石灰、生物炭配施硅/多元素叶面肥对水稻Cd积累的影响

为探明钝化剂配合叶面肥对水稻Cd积累的影响,在浙江典型Cd污染稻田,采用小区试验方式分析了对照（CK）、石灰4 500 kg/hm²（LM）、石灰+生物炭1：1混施9 000 kg/hm²（LC）3种模式基础上喷施含Si和多元素（DYS）叶面肥对水稻植株Cd积累的影响。结果表明：与CK相比,LM和LC处理糙米Cd含量分别降低70.1%和88.3%;LM配施含Si和DYS叶面肥使糙米Cd含量进一步降低45.3%和28.9%;LC配施含Si和DYS叶面肥则使糙米Cd含量进一步降低14.5%和13.7%。与LM和LC相比,加喷叶面肥使茎秆—稻谷Cd转运降低42.4%~62.7%,茎秆Cd浓度增加81.9%~123.0%,稻谷Cd浓度降低14.6%~64.2%。与CK相比,LC和LM处理显著提高土壤pH,降低土壤DTPA提取态Cd,且LC处理效果更好;LC处理使壤微生物碳、有机质、脲酶和蔗糖酶活性分别增加6.08%,7.92%,11.90%和0.72%,而LM则分别降低8.33%,14.30%,29.20%和12.10%;LM和LC分别使土壤黏粒含量降低5.73%和4.53%,且LM处理使砂粒含量增加29.70%,粉砂粒含量降低11.70%;LC则使土壤砂粒含量降低1.50%,而粉砂粒含量增加2.17%。综合分析,LC配施含Si或DYS叶面肥能够在有效降低稻米Cd含量的基础上保持土壤质量良性发展。     

黄土灰土地基的质量控制指标试验研究

对黄土灰土的物理力学性质和黄土灰土地基施工过程中的质量控制要点进行了试验研究 ,分析了各种因素对施工质量的影响。结果发现 ,在施工过程中 ,灰土地基的土体含水量、含灰量、虚铺厚度、碾压过程及碾压间隔历时等都对施工质量产生一定的影响。研究在确定灰土的最优含水量和最佳含灰量的基础上 ,提出了保证黄土灰土地基施工质量的控制系统以及为保证黄土灰土地基质量而应采取的有效措施。     

长白山地区不同植被下土壤酸度状况

The acidity regimes of representative soils on the north slope of the Changbai Mountains were examined through determinations of pH and pCa of the soil paste as well as in-situ determinations,For soils under broad-leaf forest or broad-leaf-Korean pine forest,the pH decreased from the litte to lower layers gradually until it did not change or decreased further slightly .For soils under coniferous of Erans birch forest,ther was a minimum in pH at a depth of 3-6 cm where the content of humus was high,The pCa increased gradually from the soil surface downward to a constant value.The lime potential(pH-0.5pCa) showed a similar trend as the pH in its distribution.For a given soil,the measured pH value of the thick paste,ranging from 4.5 to 5.5,was lower by about 0.5 units than the value determined by the conventional method with a water to soil ratio of 5:1 ,The pH determined in situ was even lower.It was found that there was a firly close relationship between soil acidity and the type of vegetation.The pH showed a trend of decreasing from soils under broda-leaf forest through broad-leaf-conifer mixed rorest and coniferos forest to Ermans birch forest,and the pCa showed an opposite trend in variation.