Effects of Different Lead Compounds on Growth and Heavy Metal Uptake of Wetland Rice

Effects of different lead compounds, PbCl₂, Pb(NO₃)₂ and Pb(OAc)₂, on the rice growth and uptake of lead and some microelements by wetland rice were studied. The results showed that the seed germination, rice seedling growth, chlorophyl content, grain yield and uptake of Pb, Cu, Zn, Fe and Mn by rice plant were affected by the chemical forms of Pb compounds added in soil to a certain degree. The germination rate and the amount of chlorophyl decreased remarkably with increasing Pb concentration, the root extension was restrained obviously by the presence of Pb, and the effect of PbCl₂ was more evident than that of Pb(NO₃)₂ or Pb(OAc)₂.     

新型尿素——微量元素络合肥料的原理和效应

尿素是我国主要氮肥品种,它的利用率略高于碳酸氢钱,一般为25-45%,提高尿素氮的利用率仍是一项重要课题。     

土壤有效硼与棉花不同生育时期硼含量的相关分析

硼是作物正常生长的必需元素，其在土壤的含量缺乏或过多都会影响作物的生长发育，导致产量、品质的下降。合理施用微量元素已成为生产上一项简单易行、经济有效的增产措施。     

砖红壤施用中量、微量元素对甘蔗产量与糖分的效应

在雷州半岛玄武岩发育的种植甘蔗砖红壤上施用Ca、Mg、B、Mo、Fe、Cu、Zn肥料，探究这些中量与微量元素对甘蔗的产量与糖分的效应。结果表明：Ca、Mg、B、Mo肥对甘蔗有显著增产效应，而Fe肥具有显著减产效应。B、Mo、Fe、Cu肥能显著提高甘蔗含糖量，而Mg肥具有降低甘蔗糖分的效应。Ca、B、Mo3种肥料相互配施的增产或增糖效果均不优于单施的效果。从对甘蔗产量和含糖量综合效果看，甘蔗施用B、Mo、Ca肥分别能产生显著经济效益。因此，在玄武岩发育砖红壤上种植甘蔗，建议施用Mo、B、Ca肥。     

植物生长必需的微量营养元素——镍

自１９７５年首次发现镍是脲酶的组成成分以来，镍是否是植物生长所必需的营养元素一直为许多研究者所关注，越来越多的证据表明，镍可能是植物生长所必需的微量营养元素，这不仅是由于脲酶在植物体内的氮代谢过程中起着重要作用，而且是由于植物缺镍时生长发育受到抑制，甚至不能完成生命周期，本文总结了国际上有关方面的研究进展，并讨论了影响镍有效性的土壤条件。     

豫东潮土地区大蒜喷施微量元素肥料效果试验

试验表明在豫东潮土地区大蒜喷施钼酸铵、硫酸锌、硼砂、硫酸锰、硫酸铜有明显增产效果，比对照增产幅度为1890．0～3844．5kg／hm^2，增产9．6％～19．4％；同时提高大蒜的品级，改善大蒜品质，经济效益高，比对照增收3712．17～6566．54元／hm^2，增值达16．4％～27．3％。     

甲醇微量元素溶液对凤仙花及小白菜生长的影响

对凤仙花或小白菜植株，喷淋０．１％～０．２５％甲醇溶液、微量元素溶液或两者混合溶液，植株的鲜重、干重比对照处理均表现增重效果。在小白菜的试验中，０．１％甲醇溶液处理的植株干重，在先后两次分析中，分别比对照增加１２．６％和１０．９％；而鲜重则分别增加１１．５％和１１％。在用０．２５％甲醇溶液处理凤仙花植株时，在２０ｄ内，可使植株干重增加，但继续施用时，可因药物的浓度或剂量过高，导致植株黄化，干重下降。     

Soil Micronutrients and Citrus Growth

By using nutritional diagnosis of citrus leaves and determining soil micronutrients,the relationship between soil micronutrients and citrus growth in southern China has been studied.Studies showed that there was a significant positive correlation between available micronutrients (such as Zn,Mo,Cu)in the soil and the corresponding nutrients in citrus leaves.Thus,one can roughly learn of the sufficiency or deficiency of certain nutrients in soils by analyzing citrus leaves.Rational spray of Zn B or Mo fertilizer not only improved citrus yields but also increased the total sugar of Satsuma mandarin and of Xinhui orange by 2.9 and 17.2% respectively compared with the control.Spraying Mo fertilizer increased the vitamin C content of Satsuma mandarin juice by 4.7%-8.4%,maturated fruits 7-10 days earlier and gave the peel a brighter color.The ultramicroscopic characteristics of Zn-deficient citrus leaves were investigated under an electron microscope.Results showed that the Zn-deficient leaf cell was characterized mainly by poor cytoplasm,endoplasmic reticula and ribosomes and by big starch grains in the chloroplast.As a result of spraying Zn fertilizer the structure of the cell returned to normal,the cytoplasm became rich and the amount of chloroplast increased.There also appeared a great deal of multiform endoplasmic reticula,thus promoting the photosynthesis of Zn-deficient plants.This provides a cytologico-theoretical basis for fertilization of high-yielding citrus trees.     

农业生产中的铁锰平衡问题

本文根据对菠萝和水稻的研究,论述了土壤和植物体内铁与锰的关系,认为在植物体内铁与锰的比例应保持一个平衡的关系。如果锰多铁少、比例失调,作物的正常生长将受到危害。