海水养殖废水灌溉条件下SPAC系统中水盐肥通量研究

2004年4月～10月，在半湿润的莱州地区布置蒸渗试验，研究海水养殖废水灌溉条件下SPAC系统水盐肥通量。试验设5个处理，分别为CK（种作物，不灌溉）和淋洗分额（LF）为0．1、0．2、0．3、0．4的海水养殖废水灌溉处理。结果表明：对于淋洗分额为0．1、0．2、0．3、0．4的海水灌溉处理，用于土壤蒸发和作物蒸腾的海水养殖废水量分别占菊芋生育期总蒸散量的36．5％、36．2％、37．0％、37．3％；对于上述海水养殖废水灌溉处理，土壤耕层的盐分积累量分别为91．1、94．1、98．7、107．1g；而铵态氮的积累量分别为2．00、2．29、2．27、2．82mg，硝态氮的积累量分别为1．81、1．40、1．29、0．92mg，活性磷酸盐的积累量分别为3．03、2．68、2．44、1.67mg。因此，认为海水养殖废水灌溉在供给作物水分和养分方面起到积极作用，但需采取调控措施以防耕层土壤盐分过量积累。     

渗育性水稻土渗滤液中的磷组分研究

本试验在太湖地区长江岸边砂质渗育性(漏水型)水稻土上进行,研究在麦稻轮作条件下连续两年施用不同磷肥(每季P 0、30、70、150和300 kg hm-2),稻季各层次土壤溶液中(30、60和90 cm)磷的组分,以探讨磷素在剖面中垂直纵向移动的规律。结果表明:施肥处理在施肥初期提高了30 cm处土壤溶液中溶解磷浓度,对60 cm处溶解磷浓度影响不大,对90 cm处溶解磷浓度没有影响。各处理60 cm和90 cm处土壤溶液中溶解磷的浓度几乎全部超过水体富营养化磷的阈值,故在研究该地区水体富营养化时,要注意渗漏磷排放可能的贡献。特别应指出的是,除6月13日对照处理外,各处理90 cm处土壤溶液中的磷均以溶解有机磷为主,占总溶解磷的56%~100%,表明有机磷(外源加入或内源残留的)比无机磷对环境的潜在威胁将更大。     

Ridging in autumn as an alternative to mouldboard ploughing in a humid-temperate region

In the original ridge tillage system as practiced in the US Corn Belt, ridges are formed during the growing season. Several studies have documented that this can reduce leaching of nutrients and improve fertilizer efficiency. This study was conducted to determine whether ridges formed in autumn can be used as an alternative to ploughing to reduce N leaching during autumn and winter, and thereby increase growth and N uptake of a subsequent unfertilized crop. A factorial field experiment with tillage and residues as factors was conducted during 1998–2000. Tillage treatments were autumn ridging and ploughing. Residue treatments were stubble, stubble + straw and stubble + liquid manure in order to create a gradient of C/N ratios. From the time of harvest until planting of a subsequent barley crop (Hordeum vulgare L.), inorganic N was determined 11 times in 1998–1999 and 10 times in 1999–2000 in the 0–10, 10–30, 30–60 and 60–90 cm soil layers. Growth and N uptake of barley was quantified nine times in both 1999 and 2000. Barley grain and straw yields were determined. Ridging resulted in lower levels of inorganic N in the 30–90 cm soil layer in November and a significantly higher level of inorganic N in the 0–30 cm soil layer in late April, indicating reduced leaching and increased N availability for the subsequent crop. Ridging significantly increased growth, yield and N uptake of barley whereas incorporation of straw generally reduced growth, yield and N uptake. It is concluded that ridging in autumn has a N conserving effect, and it is suggested that the potential of ridging in autumn as an alternative to ploughing is further investigated in detailed studies of solute movement, N immobilization/mineralization and crop performance.     

表层盐化土壤的灌溉淋洗需要量

通过土柱模拟实验及数值模拟计算，探讨了灌溉淋洗需要量的确定方法，并初步给出了不同作物苗期及生育期的灌溉淋洗需要量。依各种作物耐盐性的不同，苗期灌溉淋洗需要量为１９１－１３５０ｍ＾３／ｈａ；生育期灌溉淋洗需要量为６９０－３９５０ｍ＾３／ｈａ。此研究结果为土壤盐渍化的防治和进一步完善水资源的合理利用提供了理论依据。     

CC及ACQ-B防腐剂处理木材的抗流失试验

对于氨溶性季铵铜ACQ-B处理的马尾松(Pinus massoniana)及尾叶桉(Eucalyptus urophylla)试材，在吸药量为3.0～6．0kg／m^2时，按标准AWPA M11-87测定的流失率小于2.50％。比较ACQ—B与CC两种处理材，当吸药量(以CuO计)相当时，CC的流失率较ACQ—B大。ACQ—B可用于与地接触的人工林木材处理，如农用材或建材。     

河北省典型保护地蔬菜土壤硝态氮的含量和分布

调查了定州市和永年县蔬菜大棚和拱棚施肥情况 ,并采集土壤样品测定了土壤硝态氮含量。结果表明 ,蔬菜土壤硝态氮含量定州市平均比永年县高出 1 3 3～ 38 9mg/kg。表层土壤的硝态氮含量 ,定州市变化幅度 60～ 2 0 0mg/kg ,平均 94 2 5mg/kg ,永年县变化幅度为43 0～ 64 7mg/kg之间 ,平均 5 5 4mg/kg。保护地蔬菜土壤 0～ 1 0 0cm土层积累了大量的硝态氮。其中定州市蔬菜大棚土壤 1m土层内硝态氮含量平均为 80 7 0 6kg/hm2 ,永年县平均为430 32kg/hm2 ,均高于大田作物。容易造成土壤硝态氮积累和淋溶。     

冬季休闲期间土壤剖面硝态氮的移动

本文介绍了1984～1986年,在南斯拉夫甜菜主产区——伏伊伏丁那自治省进行的田间试验,结果表明,冬季休闲期间,碳酸盐黑钙土中无硝化与反硝化作用。土壤中残留的和秋季施入的硝态氮,随冬季降水下渗深度平均达160 cm,绝大部分积累在30～120 cm土层,并以60～90 cm最高。每毫米降水使硝态氮下渗0.53～0.82 cm。应用抛物线法计算定积分值公式,求得硝态氮下渗强度变化在2.28 ppm cm·mm~(-1)～8.21 ppm cm·mm~(-1)。     

Soil mineral nitrogen dynamics in fallow periods in a rainfed semiarid Mediterranean agricultural systems

Rainfed agricultural systems in semiarid Mediterranean environments are subject to erratic but often heavy rainfall events.As an agronomic practice,fallow periods can be included even within the existing European Union common policy for crop diversification.This study aimed to quantify the effects of previous mineral fertilization on soil mineral nitrogen (Nmin) content and potential nitrate leaching during no-till fallow periods of crop rotation.The Leaching Estimation and Chemistry Model (LEAC...     

有机无机肥配合对土壤磷素吸附、解吸和迁移特性的影响

通过32P示踪、薄层层析和土柱淋洗研究了经过四季不施磷肥、施用纯无机磷肥以及有机无机磷肥3种处理对土壤磷素迁移的影响。结果表明:有机无机肥配合处理的土壤磷吸附亲和力常数和最大吸附量显著低于化肥处理,磷累积解析量高于化肥处理,而32P在薄层板的迁移距离显著高于化肥及对照处理;淋洗试验中有机无机肥配合处理土壤中的32P最先在淋洗液达到13.1mL时出现,而化肥及对照的32P则分别在淋洗液达19.0和19.8mL时出现;在淋洗液体积达到50mL时,对照、化肥及有机无机肥配合处理淋出的32P总量分别为总加入量的1.6%、8.4%和9.8%。有机无机肥配合可以减少土壤磷素的固定,增强磷在土壤中的移动,提高磷的有效性。     

全自动淋洗-定氮仪测定土壤阳离子交换量的相关探讨

土壤阳离子交换量(CEC)是指土壤胶体所吸附的各种阳离子的总量[1]。常作为评价土壤保肥能力的指标，它反映土壤的负电荷总量和表征土壤的化学性质。采用全自动的淋洗仪和定氮仪完成土壤阳离子交换量的测定，采用合适的滤纸，分析标准土壤，计算其准确度和精密度能符合标准要求，将本方法与LY/T 1243-1999《森林土壤阳离子交换量的测定》标准方法同时测定7个不同土壤，将成对数值进行t检验，结果表示两种方法的测定结果没有显著性差异。故日常工作中可以采用全自动淋洗-定氮仪法分析全自动淋洗-定氮仪项目，从而做到省时，便捷。