水肥减量对设施连作茄子产量、品质及黄萎病发病率的影响

【目的】提高黄萎病高发区设施连作茄子产量和品质,降低黄萎病发病率和病情指数。【方法】在塑料大棚内,研究了水肥减量(灌水量和施肥量均为常规的80%、70%、60%、50%、40%)对设施连作茄子生长、产量、品质、根际微生物以及黄萎病发病率和病情指数等的影响。【结果】①随着水肥量的降低,茄子根际大丽轮枝菌微菌核数量,黄萎病病情指数和发病率也降低。②50%水肥处理,相比其他处理,茄子根际大丽轮枝菌微菌核数量与种植前相比没有显著增加,黄萎病病情指数和发病率最低。③50%水肥处理的茄子生长状况、果实性状最好,产量、品质最高;根际有害真菌数量降低,细菌、放线菌数量增加。【结论】在设施茄子黄萎病发病较严重地区,可通过合理的水肥减量措施,如水肥量减半,在保证设施连作茄子正常生长前提下,降低设施连作茄子黄萎病发病率,且获得最大产量和较高品质。

生物有机肥对盐渍土壤水盐动态及番茄产量的影响

为探讨生物有机肥对不同类型盐渍土壤(设施次生盐渍土、滨海盐渍土)水盐动态和作物产量的影响,采用盆栽试验方法研究不同施肥(不施肥、化肥、生物有机肥、生物有机肥+化肥(比例为1∶1))处理对盐渍土土壤含水率、电导率、盐分离子组成变化和番茄产量、水分利用效率的影响。结果表明:(a)单施生物有机肥处理和生物有机肥+化肥处理均可以提高土壤含水率;(b)单施生物有机肥处理的土壤电导率最低,其次为生物有机肥+化肥处理;(c)对于设施次生盐渍土,与化肥处理相比,单施生物有机肥处理和生物有机肥+化肥处理的土壤盐分离子总量分别降低了23.63%和15.60%;(d)对于滨海盐渍土,与化肥处理相比,单施生物有机肥处理和生物有机肥+化肥处理的土壤盐分离子总量分别降低了22.34%和10.32%;(e)番茄收获后,设施次生盐渍土各处理的NO_3^-和SO_4^(2-)在土壤盐分中的占比降低,滨海盐渍土各处理的Na^+、K^+和Cl^-占比降低;(f)单施生物有机肥处理最有利于土壤微生物的增加,其次是生物有机肥+化肥处理;设施次生盐渍土中生物有机肥+化肥处理的番茄产量最高,比单施生物有机肥处理增产165.5%;(g)施用生物有机肥可以提高设施次生盐渍土的作物产量和灌溉水利用效率,而单施化肥则可能会造成作物绝产;(h)施用化肥虽然提高滨海盐渍土的作物产量,但施用生物有机肥处理的灌溉水利用效率相对较高。

烤烟水肥一体化技术研究与应用进展

本文综述了近年来烤烟水肥一体化技术研究与应用进展,包括系统组成及水肥运筹,以及水肥一体化技术对烤烟生长发育、生理生化、经济性状、品质性状等方面的影响;同时结合生产实际对当前水肥一体化技术应用于烤烟生产上需要解决的技术问题和研究方向进行了展望,相关成果可为提升该技术在烤烟生产上的应用推广效果提供有益参考。

基于Gardner模型的黔西南土壤水分特征分析

【目的】了解黔西南州不同地区土壤剖面(0~60 cm)持水特性的差异。【方法】在实验室内利用压力膜仪法测定了各土壤的水分特征曲线,并分析其土壤水分特征。【结果】黔西南州各植烟县不同土层土壤水分特征曲线匀可采用Gardner模型拟合,不同烟区土壤水分常数及持水特性有明显差异。其中兴义、贞丰、安龙和普安土壤持水性能强弱表现为40~60 cm>20~40 cm>0~20 cm,晴隆和兴仁烟区土壤持水性能表现为20~40 cm>40~60 cm>0~20 cm;各植烟县烟田0~20 cm土层土壤持水性强弱顺序为兴义,安龙,晴隆,贞丰,普安和兴仁;20~40 cm土层土壤的持水性强弱顺序为兴义,安龙,晴隆,兴仁,贞丰和普安;40~60 cm土层土壤的持水性强弱顺序为兴义、安龙、普安、晴隆、贞丰和兴仁。【结论】同一植烟县深层土壤持水能力强于表层土壤,不同植烟县间的土壤持水性也存在明显差异。

土壤调理剂用量对酸性土壤肥力影响的综合评价

【目的】客观评价碱性土壤调理剂改良后的土壤肥力水平,为酸化土壤的科学改良提供参考。【方法】以小白菜为研究对象,对土壤调理剂不同用量下的酸性土壤肥力进行综合评价。运用主成分分析并计算变量的Norm值,结合肥力指标间的相关关系筛选出酸性土壤肥力评价的高度敏感性指标进入土壤肥力评价的最小数据库集(MDS)。通过隶属度函数实现评价指标量纲统一,绘制隶属度函数雷达图直观反映土壤肥力的整体状况及肥力单因素状态。采用2种指数模型对改良后的土壤综合肥力进行评价。【结果】筛选出pH、交换性Ca^2+、总氮、交换性Mg^2+、有机质作为酸性土壤肥力评价指标,根据雷达图及指数模型可知,施用土壤调理剂可以提升酸性土壤肥力,肥力提升的程度受调理剂用量控制,土壤调理剂的推荐用量为450 kg/hm^2。【结论】土壤调理剂用量造成的pH和交换性Mg^2+差异是肥力的限制因子;土壤肥力是小白菜产量的决定因素,单个肥力指标的改善虽然有一定程度的改良效果,但是不能起到显著增产作用,土壤酸化改良应参考肥力综合值进行改良效果评价。

Effect of EM Bokashi application on control of secondary soil salinization

In order to ameliorate saline-alkaline soil, EM Bokashi has been applied to rice production in conjunction with subdrainage in Ningxia Autonomous Region and Zhejiang Province. The preliminary results can be summarized as follows： EM Bokashi can increase soil organic matter content, improve soil porosity and permeability, and raise the soil＇s levels of available nutrients; and EM Bokashi combined with subdrainage treatment is more effective in controlling secondary soil salinization and raising the grain yield and quality than other treatments. The results suggest that EM Bokashi can reduce the necessary amount of chemical fertilizer application, thereby improving the agricultural environment, and that the introduction of EM Bokashi into systems of secondary soil salinization control systems has resulted in significant benefits.

基于微区设计的多雨地区烟田土壤氮素平衡研究

为探明多雨地区烟田土壤氮素平衡状况,采用15N同位素示踪试验研究了烟草大田生育期内降雨量900～1 100 mm条件下,烤烟对氮素的吸收利用及烟田肥料氮的去向。结果表明,随施氮量增加,烤烟对肥料氮的吸收量有增大趋势,但氮肥利用率降低,肥料氮在土壤中的残留量及肥料氮的径流、渗漏和其他形式损失量都显著增大。在施氮量90～150 kg/hm2范围内,烤烟氮肥当季利用率由31.38%降至21.68%,肥料氮的土壤残留量、径流损失量、渗漏损失量和其他形式损失量分别达施氮量的27.65%～30.51%、22.42%～25.79%、12.09%～15.16%和6.47%～10.29%。烟田残留的肥料氮在第2年(季)被烤烟吸收利用率为7.10%～8.15%,仍在土壤中的残留量占施氮量的8.89%～9.95%,径流、渗漏和其他形式损失量分别占施氮量的4.46%～4.68%、5.73%～6.59%和1.16%～1.37%。因此,肥料氮在烟田土壤中残留量较高,径流和渗漏损失量较大是多雨烟区烤烟氮肥利用率低的主要原因。适当控制氮素用量,减少肥料氮的径流和渗漏损失是提高烤烟氮肥利用率的主要途径。

Effects of compound microbial inoculant treated wastewater irrigation on soil nutrients and enzyme activities

Wastewater treated by compound microbial inoculant(CMI)in agricultural irrigation can enrich soil fertility and decompose the possible pollutants.In this study,a greenhouse experiment using tomato as the model crop was performed to investigate the effects of treated wastewater irrigation on soil nutrients and enzymes.For this purpose,certain parameters were measured,including soil total nitrogen(N),nitrate N,total phosphorus(P),available potassium(K)and the activities of the enzymes urease,acid phosphatase and catalase in soils irrigated with fresh water,wastewater and CMI-treated wastewater under three amount of irrigation water.The results showed that irrigation with both treated and untreated wastewater significantly increased soil total N,total P,and available K,however the treated wastewater showed higher effects on soil enrichment,especially on available K.The activity of soil urease and acid phosphatase reached highest with treated wastewater irrigation,whereas wastewater irrigation increased the activity of catalase obviously.Soil enzyme and nutrient with fresh water irrigation decreased with increasing water amount;the content of soil urease,nitrate-nitrogen,total N and total P in treated wastewater and wastewater irrigation rose with increasing water amount,but the highest activity of acid phosphatase and the lowest activity of catalase were found in medium irrigation water amount.Under the condition of tomato cultivation,total N,nitrate N and total P were closely correlated with soil urease and catalase;there were significant positive correlation among soil urease,catalase,total N,nitrate N and total P;there existed significantly positive correlation between acid phosphatase and all measured soil nutrient indexes.The results suggested that irrigation with CMI-treated wastewater is a security and effective strategy to agricultural land management.

Irrigation scheduling for corn in a coastal saline soil

Currently,water scarcity is serious and the irrigation scheduling with efficient water use becomes important in China.In this study,irrigation systems were scheduled in the saline area along Laizhou Bay.Field study was conducted to determine the relation of irrigation regime and crop yield from 2010 to 2012,and the representative rainfall years(high-flow year,normal-flow year and low-flow year)were calculated by analyzing rainfall frequency over 30 years.Six irrigation regimes were set according to local farmers’practices.Irrigation amounts of T1,T2,T3,T4,T5 and T6 were 225.0 mm,270.0 mm,337.5 mm,300.0 mm,360.0 mm and 450.0 mm,respectively,with the same frequency of four times.The results showed that soil salt content decreased with the increase of irrigation water amounts.The corn yield varied from 6560 kg/hm2 to 8060 kg/hm2.The highest yield was obtained from T5.Production functions related to irrigated water(I,mm)for corn yield(Y,kg/hm2)was Y=−0.0397I2+1059.6(R2=0.8892).Aiming at high corn yield,total water supply(irrigation and rainfall)to corn crops was 859 mm.Precipitation amounts at low-flow year(p=80%),normal-flow year(p=50%)and high-flow year(p=20%)were obtained by the simulation of rainfall frequency curve,which were 348 mm,457 mm and 604 mm respectively in the whole growth period(from late June to mid-October).In order to obtain the highest theoretical corn yield,according to field results and rainfall,the optimum irrigation frequency at low-flow year,normal-flow year or high-flow year was four times for corn in the saline area along Laizhou Bay.