几种土壤调理剂改良大棚种植草莓土壤的效果

随着草莓产业的稳定高效发展,设施草莓大棚土壤连作障碍问题日益突出.采用硅钙钾镁、钙镁磷、月桂醇乙氧基硫酸铵、天然海洋萃取物碳酸钙与椰子提取物混合物和聚丙烯酰胺5种土壤调理剂进行了小区试验,分析了不同处理下草莓种植大棚的土壤养分、酶活、盐分以及草莓的产量和品质.结果表明,硅钙钾镁是改良大棚草莓连作障碍土壤中比较理想的土壤...     

日光温室草莓立体栽培智能控制系统

立体栽培是将原地面的种植提升到温室内空间高度层面,这不仅使作物生长的感温层发生改变、接收到更多的日光照射,还解决了日光温室中的草莓生产管理、观光、摘菜的难题,是传统草莓种植的一次改革。但对于这样一种新的种植模式,目前还未有成熟的集高架栽培设施、滴灌、营养液配比、光照、通风、施药、温湿度等控制为一体的集成体系出现。该文介绍了一种电动式立体栽培机构,研究了一种日光温室草莓立体栽培智能控制系统。其核心内容论述了基于复杂农业大系统控制理念下,突破传统意义上的温室环境控制概念,考虑被控制量的解耦,将以往温室环境参量和作物生长参量分开,建立温室环境控制和作物生长控制2个并列的子控制系统,并在协调控制器作用下、以作物生长模型输出作为控制约束之一对各子系统进行调控。给出了基于Q学习的多Agent体协调算法,并以草莓采光随动控制和草莓根部加温控制进行了验证。该控制系统已在北京市第七届世界草莓大会日光温室草莓立体栽培中得到了成功应用。试验表明在控制草莓生长方面取得了满意的效果,草莓的挂果期比传统种植平均提前40 d,草莓的果实体积平均增大22%,出产量平均提高33%。     

不同轮作方式下大棚草莓产量及土壤生物学特性

试验研究了不同轮作方式下大棚草莓产量、土壤微生物区系和土壤4种酶活性的变化,结果表明:草莓-闷棚、草莓-水稻轮作方式草莓产量及效益明显比草莓-甜瓜旱地轮作方式高,且土壤pH值高,盐分积累少,黄萎病发生率低。草莓-闷棚、草莓-水稻轮作方式的草莓土壤微生物总数比草莓-甜瓜旱地轮作多,其中细菌所占比例达95.92%~96.21%,高于草莓-甜瓜旱地轮作的89.91%,细菌与真菌之比达649~787,为草莓-甜瓜旱地轮作的10倍左右。草莓-闷棚、草莓-水稻轮作明显提高了土壤转化酶的活性。实行草莓-闷棚和草莓-水稻水旱轮作方式,可让大棚草莓的土壤障碍得到缓解或消除,实现可持续生产。     

草莓温室太阳能热泵系统阶梯式供暖特性

运用太阳能热泵系统为草莓温室供暖,能有效提升草莓的产量和品质。为探究温室内立体栽培的供暖特性,以及相匹配的太阳能热泵系统的供暖系数(coefficient of performance,COP),该文设计并搭建了太阳能热泵阶梯式供暖系统。以"京藏香"草莓为试材,分析了距离地面0.5、1.0、1.5及2.0 m不同阶梯高度的空间温度,对比了阶梯式供暖的太阳能温室和未供暖的普通温室内的草莓品质及产量。结果表明,在北亚热带低纬高原山地季风气候地区,冬季采用太阳能热泵系统为温室供暖的COP值在3.02~5.15之间。在太阳能温室内种植的草莓产量是普通温室产量的1.56倍,可溶性固形物含量的平均值达10.5%。在太阳能热泵系统阶梯式供暖的温室中,距离地面1.0~1.5 m高度范围内的供暖效果较好,且放置于1.0 m阶梯上的草莓与其他高度的草莓相比,产量最高品质最优,其单果最大值为32.3 g,可溶性固形物含量为12.5%,因此,采用阶梯式供暖的温室中,距离地面1.0 m高度的温度更适宜草莓生长需求。     

云南设施土壤盐分累积特征研究

研究了云南不同区域、不同种植年限的大棚设施土壤的盐分累秘特征.结果表明:云南设施土壤耕层盐分含量为0.50～4.22 g/kg,平均为1.76 g/kg;大棚种植年限长的地区,土壤表层盐分含量累积明显;随着大棚种植年限的延长,盐分含量、EC值呈上升趋势;随着土壤层次的加深,盐分含量、EC值逐渐降低;Na离子(交换性Na和可溶性Na)不是导致设施土壤盐害的决定性因素.     

Effect of soil wetting and drying cycles on metolachlor fate in soil applied as a commercial or controlled-release formulation

A controlled-release formulation (CRF) has been developed for metolachlor, which reduced its leaching in a sandy soil and improved weed control in comparison with the commercial formulation. The current study tested the effect of soil wetting and drying cycles (WDCs) on metolachlor fate (desorption, leaching, and weed control) applied as the CRF and as the commercial formulation. Metolachlor adsorption to a heavy soil (Terra-Rosa) was predominately to the clay minerals and oxides. Metolachlor release from a heavy soil subjected to WDCs was higher than its release from the soil not subjected to WDCs. Consequently, a bioassay in soil columns treated with the commercial formulation indicated enhanced metolachlor leaching in heavy soils under WDCs. In contrast, when metolachlor was applied as the CRF, leaching was suppressed and not affected by WDCs. These results emphasize the advantages of the CRF also in heavy soils subjected to WDCs.     

Evaluation of pumice as a perlite substitute for container soil physical amendment

Abstract

Shallow‐drained horticultural soils utilized in containers, sporting areas, and landscape sites tend to retain excess water and be poorly aerated as a consequence of capillary retention following irrigation or precipitation. This problem is usually corrected by soil physical amendment with coarse‐textured particulates which add pores sufficiently large to drain and provide adequate aeration. A variety of materials are used for soil physical amendment. One of the most common and successful amendments is perlite. This study examined the feasibility of using pumice, a very similar mineral, as a substitute for perlite in soil amendment.

The physiochemical properties of pumice important to its use as a container soil amendment were found similar to those of perlite.     

后墙立体栽培草莓提高冬季日光温室内温度

在日光温室的后墙上,采用管道无土栽培方式进行蔬菜或草莓生产,可以提高温室空间利用率和作物种植量,但可能会出现因为管道和植物的挡光而减少后墙蓄热、降低冬季温室温度的问题。为此,通过冬季连续31 d的温度监测,在3种典型气象（晴天、阴天、雪天）条件下,对比分析了有后墙立体基质栽培的日光温室（solar greenhouse with equipment,ESG）和无后墙立体栽培的日光温室（solar greenhouse with no equipment,NSG）温度环境的变化。监测结果表明,ESG的月平均气温较NSG高0.84℃,其中最大日温差为2.22℃,最小日温差为0.14℃。晴天条件下,ESG的日平均冠层温度和1.5 m高度处的空气温度分别是12.72和13.04℃,NSG分别是10.68和11.04℃;ESG的冠层温度最低值是4.68℃,而NSG最低值是4.10℃。可见,ESG较NSG的气温要略高一些;阴天和雪天条件下,2种温室内的温度环境无显著差别。因此,利用日光温室后墙进行立体基质栽培草莓,不但没有降低反而提高了冬季温室内的温度,是一种可行、值得推广应用的温室高效栽培技术。     

强化拮抗菌有机肥在连作大棚草莓上的应用效果研究

采用室内平板培养、气候箱内土壤处理及盆栽和大棚试验相结合的方法,研究了以腐熟中药渣堆肥为原料制备的液体肥料在强化了拮抗微生物前后对草莓枯萎病菌生长的抑制作用及对病害的防治效果,结果表明:普通液肥和两种强化液肥对两种草莓病原真菌的生长都有不同程度的抑制作用;三种液肥经辐照灭菌后均丧失了对病原真菌的抑制作用;两种强化液肥处理土壤10～15d后能显著抑制土壤中草莓枯萎病菌的生长繁殖而降低土壤中病原菌的数量。盆栽试验表明:普通液肥辅照灭菌后对草莓枯萎病仍有一定的防效,但显著低于没灭菌的液肥;两种强化液肥对草莓的盆栽防效显著高于普通液肥。大棚小区试验显示:施用有机液肥的三个处理的草莓产量显著高于常规对照,而发病率显著低于常规对照;分别强化了两种拮抗菌的液肥对病害的防效均好于未强化的液肥;施用液肥对根际土壤酸化和盐分积累有一定的修复效果,使小区草莓增产达93～110%,畸形果率降低23.5%,并对草莓品质有一定程度的改善。强化了拮抗菌的有机液肥对草莓连作障碍的防治效果显著提高。     

Evaluation of soil test methods for estimation of available phosphorus in some Portuguese soils: A greenhouse study

Abstract

The Egnér‐Riehm method for estimating plant‐available soil phosphorus (P) has been used as the standard soil testing method in Portugal for making fertilizer recommendations. However, this method does not accurately reflect the available P status for wheat in some representative soils from the South Region of the country. Therefore, a pot experiment was established with four Luvisols (LVx, LVv, and two different LVh soils) from the South Region of Portugal in order to evaluate the Egnér‐Riehm, Bray I, Bray II, Olsen, and Anion Exchange Resin (AER) methods for their ability to estimate available P in those soils. Wheat (Triticum aestivum L., cv. Panda) was used as test the crop. The experiment was arranged into a randomized complete block design with three replications and five rates (0, 50, 100,150, and 200 mg kg^‐1) of P added to each soil. Critical soil P levels for LVx were established in case for Bray I (27.9 mg kg^‐1), Bray II (33.5 mg kg^‐1), Egnér‐Riehm (25.4 mg kg^‐1), and AER (14.7 mg kg^‐1) soil test procedures. Regarding the other soils, the critical soil P levels could not be estimated. The obtained results confirm that the development of an universal soil test P exti action is of great importance, and that further research should be conducted in order to evaluate routine soil fertility tests in different pedoclimatic environments.     

Impact of soil solarization on the ciliate community structure of a greenhouse soil

Soil solarization is an ecologically friendly method of controlling various plant pathogens and pests, but also affects non-pathogenic members of the soil biota. Here, we studied the impact of soil solarization on the community structure of soil ciliates using a culture-independent molecular approach, namely denaturing gradient gel electrophoresis (DGGE) of targeted 18S rRNA gene fragments. Greenhouse soil with added organic fertilizers was solarized for 33 days at an average temperature of 47–48°C. Solarization caused a drastic change in the ciliate community. The variation between replicates was large, which suggested that the distribution of ciliates was spatially heterogeneous in the soil, probably due to their decreased numbers. In contrast, non-solarized soil had a stable and homogeneous ciliate community during the experimental period. In solarized soil, most of the original ciliate community recovered 76 days after solarization. Sequence analysis of DGGE fragments indicated that both r-selected and K-selected species of ciliates were affected by solarization but recovered with time after solarization. Our results demonstrated both the vulnerability and resilience of the ciliate community to soil solarization and also the utility of using molecular-based analysis of ciliate communities as bioindicators of soil stress caused by solarization.     

Effect of drip application of ammonium thiosulfate on fumigant degradation in soil columns

Low permeability tarps can effectively minimize fumigant emissions while improving fumigation efficacy by retaining fumigants under the tarp. However, when planting holes are cut through the tarps, high-concentration fumigants may be released and result in environmental and worker safety hazards. In a 11-day column study, we explored the effect of drip irrigation application of ammonium thiosulfate (ATS) on 1,3-dichloropropene (1,3-D) and chloropicrin (CP) degradation in soil. Decrease of 1,3-D and CP concentrations in soil-gas phase followed a three-parameter logistic equation for all treatments. It was slowest in the control with a half-life ( t 1/2) of 86.0 h for 1,3-D and of 16.3 h for CP and most rapid when ATS was applied at 4:1 ATS/fumigant molar ratio with a half-life of 9.5 h for 1,3-D and of 5.5 h for CP. Our results indicate that applying ATS via the drip-irrigation systems to soil can accelerate fumigant degradation in soil and thus reduce emissions. This technical solution may be applicable in raised-bed strawberry production where drip-application of fumigants under tarps has become common.     

Evaluation of a radiosity based light model for greenhouse cucumber canopies

Light distribution is a key factor of developmental and growth processes, and strongly depends on the foliage distribution which is affected, e.g., by the arrangement of the plants in the canopy. The precise simulation of the light distribution on organ level is an essential component for dynamical plant models which incorporate structural and physiological adaptions of plants to their environment. Combinations of static 3D plant models with 3D light models are used for analyzing the complex light distribution on leaf level in silico, but detailed measurements for evaluation of simulation results are almost non-existent. This study addressed the evaluation of a model on a high level of detail using individual leaf based light measurements in canopies of cucumber (Cucumis sativus L.). We combined a static 3D plant model derived from digitized plants on an individual organ scale with a mock-up of the surrounding canopy and a 3D radiosity based light distribution model. Variations of plant density and spacing were analyzed to cover a range of canopy architectures. An exclusion of components of the light environment by applying a shading encasement followed by a successive uncovering allowed investigating the scene under increasing levels of complexity. The combined 3D plant-light distribution approach allowed determining the interaction of the light directions and the canopy architecture as well as differences in the accuracy of the simulations. Depending on canopy architecture and shading treatment, the light distributions covered a range from exponentially shaped vertical gradients in encased treatments to nearly flat light profiles in nonencased conditions. In conclusion, simulations of leaf level PAR based on combinations of detailed 3D surfaced-based plant and light distribution models are suitable to derive light-induced physiological responses on organ level.     

日光温室番茄控制土壤深层渗漏的灌水量指标

针对菜田灌溉水肥渗漏问题,采用田间试验和室内分析相结合,研究不同灌溉方式下日光温室番茄不同生育期根系垂直分布特征,在此基础上,进一步研究了膜下沟灌方式下不同灌水量番茄田土体水分的垂直分布特征及灌水量与土壤水在根层外渗漏的关系。结果表明,日光温室番茄主要根系层为0～40 cm,最深根层为60 cm。在灌水量7.5～ 22.5 mm范围,灌溉后番茄田不同土层水分增加量呈垂直递减;在灌水量7.5～45 mm范围,灌溉水根层外的渗漏率与灌水量呈线性相关;该文以满足根层水分有效供给和控制根层外渗漏为目标,确定日光温室番茄花果期和采收期适宜每次灌水量为15～22.5 mm。研究结果可为确定浅根性蔬菜根-水同位管理灌溉指标提供依据。     

基于热脉冲方法的南方红壤蒸发原位监测

基于热脉冲技术的能量平衡方法是一种原位实时监测土壤蒸发速率技术。热脉冲方法的准确性受地表气象条件、土壤类型等因素影响,目前该技术多应用于质地较砂北方旱地土壤。为进一步验证热脉冲方法在质地较黏的南方红壤上监测蒸发速率的适用性,该研究利用热脉冲传感器与微型蒸渗仪开展了为期30 d的监测试验,对比了热脉冲能量平衡方法与微型蒸渗仪测得日蒸发速率以及累积蒸发量,并通过监测土壤含水率变化和气象因子,评价了红壤区土壤蒸发的主要影响因素。结果表明,热脉冲方法测得的日蒸发速率与微型蒸渗仪监测值变化趋势相同,试验期间两种方法测得日蒸发速率最大相差0.80 mm/d,最小相差0.02 mm/d,决定系数R2=0.52。两种方法测得的累积蒸发量随时间变化值之间具有更强的相关性（R2=0.99）,30 d内微型蒸渗仪监测的总累积蒸发量为19.3 mm,热脉冲方法监测的累积蒸发量为24.4 mm。由于降水影响,微型蒸渗仪漏测了7 d的蒸发速率,剔除该7 d数据后,二者仅相差4.6%。相比于传统的微型蒸渗仪法,热脉冲方法具有自动化的优点,且能够实时监测剖面微尺度（mm尺度）上蒸发动态。研究区红壤的日蒸发速率与各因子的相关程度由大小为土壤含水率、净辐射、风速、气温。研究结果表明热脉冲能量平衡方法能够准确地监测南方红壤区土壤蒸发动态,研究可为红壤区水热循环研究提供技术和理论支撑。     

Organo-clay formulation of acetochlor for reduced movement in soil.

This study aimed to design ecologically acceptable formulations of acetochlor by adsorbing it on montmorillonite exchanged by a small organic cation, phenyltrimethylammonium (PTMA). Adsorption of acetochlor on the clay mineral exchanged with different organic cations and its release from these complexes were determined by GC and modeled by Langmuir equation. Interactions between acetochlor molecules and the exchanged organic cation on the clay surface were studied by Fourier transform infrared spectroscopy. Leaching of acetochlor in soil was determined by a bioassay using a column technique and Setaria viridis as a test plant. The adsorbed amounts of acetochlor on montmorillonite exchanged by PTMA at a loading of 0.5 mmol/g of clay were higher than at a loading up to the cation-exchange capacity, i.e., 0.8 mmol/g, and were higher than obtained by using a clay mineral exchanged by other organic cations. Preloading montmorillonite by PTMA at 0.5 mmol/g yielded maximal shifts of the infrared peaks of the herbicide. The above formulation of acetochlor yielded slow release in water and showed improved weed control in field and greenhouse experiments in comparison with the commercial formulation. The PTMA-clay formulation of acetochlor maintained herbicidal activity in the topsoil and yielded the most significant reduction in herbicide leaching and persistence under field conditions. The application of this formulation can minimize the risk to groundwater and can reduce the applied rates.     

装配式日光温室砌筑不同蓄热墙体的增温和草莓栽培效果

针对西北沙漠地区日光温室冬季夜间室内低温的问题,以新疆和田使用的装配式日光温室为研究对象,通过在温室内北侧砌筑砖墙体、砌块墙体和砌块填充沙土墙体3种材质的蓄热墙体,采用PT100铂电阻温度传感器对试验温室墙体、室内温度进行测试,并进行草莓栽培试验,用ACS-30型天平、LH-B55型数显折光仪进行草莓质量、可溶性固形物含量测量。由试验数据得,3种蓄热墙体体积、尺寸相同条件下,蓄热性能依次是:砌块填充沙土墙体砌块墙体砖墙体。装配式日光温室内砌筑砖墙体、砌块墙体和砌块填充沙土墙体,使得室温较装配式日光温室早晨07:00分别增加2.2、2.9和3.8℃。采用同样的种植管理技术,栽培的草莓开花期分别比原装配式日光温室早7、11和14 d,成熟期早14、17和20 d,单棚产量依次高24.2%、30.1%和33.4%,比装配式温室的草莓可溶性固形物质量分数平均值高1.4、2.1和2.6个百分点。进一步验证了墙体对日光温室热贡献的重要性,且砂浆砌块墙体比砖墙体增温效果明显,该墙体温室更适宜草莓生长。新砌筑墙体蓄热量与装配式温室热负荷计算数值一致,表明在没有其他加温设施的情况下,温室内新砌的墙体是室内夜间热源,可使温室内温度增加。该文为西北沙漠区日光温室墙体蓄热材料和结构设计提供参考,为日光温室内砂浆砌块的应用研究提供了依据。     

我国水土流失的经济影响评估

在我国水土流失影响分析与损失分类的基础上,构建系列评估模型方法,对1990年和2000年水土流失造成的直接经济损失进行分类与分区评估。结果表明：水土流失对我国国民经济的影响显著,尤其是在水土流失比较严重的西南和西北地区;2000年全国水土流失的面积和强度均较1990年有所降低,但经济损失却增加了34．8％。水土流失防治工作任重而道远。     

Norflurazon mobility, dissipation, activity, and persistence in a sandy soil as influenced by formulation

Five ethylcellulose (EC) microencapsulated formulations (MEFs) of norflurazon were prepared and applied in soil to study their mobility, dissipation, activity, and persistence. The results show that the release into water of norflurazon from EC microspheres was retarded when compared with that of commercial herbicide. The mobility of norflurazon from MEFs into soil columns has been greatly diminished in comparison with that of its current commercial formulation (CF). Norflurazon distribution at different depths in the soil was higher in the upper ring (up to 50% of the initial application). In contrast, the residues from commercial norflurazon along the complete soil column were only about 2%. Degradation and bioassay experiments showed that the MEFs had greater persistence (t1/2 values were 7.72 and 30.83 weeks for CF and MEFs, respectively) and herbicidal activity than the commercial formulation. The use of these formulations can be advantageous, because they can minimize the risk of groundwater contamination and permit herbicide use at reduced rates, maintaining the desired concentrations of herbicide in the topsoil layer for longer periods of weed control.     

Evaluation of two soil conditioners for limiting post‐fire erosion as part of a soil conservation strategy

Soil conservation is a major concern for catchments affected by forest fires. The lack of vegetation cover and the development of soil water repellency increase the risk of topsoil erosion. This paper evaluates two soil conditioners (a wetting agent and a polyvinyl acetate) for limiting overland flow and erosion in inter‐rill areas. Unburned and burned soil samples were treated with one or both soil conditioners. The effects of these treatments on run‐off, water retention, erosion and plant growth were assessed using laboratory rainfall simulations. Polyvinyl acetate had little impact on water retention but was effective in reducing soil loss. The surfactant had little impact on water run‐off or soil loss but substantially improved water retention and plant biomass production. Application of soil conditioners on post‐fire areas could be a valuable technique in a soil conservation strategy. To maximize their benefits, soil conditioners could be applied with seeding using hydroseeding techniques and be limited to particular areas, such as paths and roadsides. Laboratory results indicate that field testing should also be carried out.