不同耕作方式对辽西褐土物理性状及玉米根系分布的影响

通过连续3年大田试验，对旋耕、翻耕、深松3种耕作方式下的土壤物理性质、玉米根系分布和产量进行测定。结果表明，与翻耕和旋耕相比，深松显著增加了玉米田土壤耕层厚度和降低了犁底层厚度。在中下层土壤，深松还降低了土壤紧实度和容重，改善了土壤的孔隙状况，有利于玉米根系向下生长，使得中下层土壤的玉米根系不仅更丰富，而且占总根系量的比例也更高，最终提高了玉米产量。本研究表明，深松耕作有利于改善辽西褐土区土壤结构和促进玉米生长。     

耕作方式对主要粮食作物影响的研究综述

笔者通过对相关资料的整理与分析,阐述了常见不同耕作方式对主要粮食作物根系特性、光合效应、品质指标及产量的影响,分析了未来农业生产中进一步加强对耕作方式研究的必要性和重要性,并指出今后农业生产中应在结合中国国情的基础上注重根据区域生态环境、土壤属性、作物种类及茬口类型选择适宜的耕作方式,试图为中国农业生产中耕作方式更加合理的选择与运用及作物产量的提高和耕地的可持续利用提供科学依据和理论帮助。     

蔬菜洪涝灾后田间管理主要技术措施及对策

持续大到暴雨导致蔬菜田块遭受水淹,易造成涝灾、渍害,田间湿度大,病害多发,落花、落果较多,出现沤根、烂根、死棵、绝收现象。为搞好生产救灾,将灾害损失降至最低,针对洪涝灾害影响、灾后田间管理、灾后恢复生产等方面阐述了蔬菜灾后生产技术措施,对不同受灾程度的田块提出了清沟沥水、及时追肥、抢收抢种和加强病虫害防治等田间管理技术对策。     

有机培肥与耕作方式对稻麦轮作土壤团聚体和有机碳组分的影响

为了明确不同外源有机物和耕作方式对土壤地力培育的影响,以水稻-小麦轮作系统为对象,通过2个年度(2016—2018年)大田试验研究了外源有机物(秸秆和有机肥)和耕作方式及其交互作用[稻麦秸秆还田配合旋耕(SR),稻麦秸秆还田配合翻耕(SP),秸秆不还田、增施有机肥配合旋耕(MR),秸秆不还田、增施有机肥配合翻耕(MP),秸秆不还田、不施用有机肥、旋耕深度15 cm(CKR)]对土壤团聚体和有机碳组成的短期影响。结果表明:SR处理能够降低水稻季土壤容重并增加总孔隙度。相比CKR,小麦季SR处理显著增加0.05mm水稳性团聚体含量,增加量为7.2%。此外,外源有机物和耕作对土壤有机碳活性组分具有显著影响。其中,易氧化有机碳(EOC)主要受耕作与有机物交互作用影响,酸水解有机碳(LPIc和LPII_c)主要受耕作措施的影响, SR处理的土壤EOC和LPI_c含量比CKR提高0.3～2.6 g·kg~(-1)。颗粒有机碳(POC)主要受外源有机物的影响,并且秸秆还田处理POC平均含量高于增施有机肥处理,增加量为0.75g·kg~(-1)。短期内,外源有机物和耕作及其交互作用对稳定性有机碳(黑碳和矿物结合态有机碳)的影响较小。综上,秸秆还田配合旋耕有助于提高土壤水稳性团聚体和活性有机碳的含量(EOC、LPI_c和POC)。     

桔小实蝇在云南蒙自地区的发生规律研究

桔小实蝇寄主范围广、繁殖量大、危害重,是世界性的重要检疫害虫。本文通过调查分析,研究了云南蒙自市的海拔、防治措施、果树种类三因素对桔小实蝇种群动态的影响。结果表明,桔小实蝇在1412 m低海拔地区的种群数量大于1608 m和1700 m高海拔地区的,这说明海拔越高,桔小实蝇种群数量越小,危害也越小。根据在相似海拔地区相同果园桔小实蝇种群数量的比较,发现严格按照本课题组探索的防治措施做好桔小实蝇防治能收到良好的效果。蒙自市的水果成熟期不同,随着各种水果的成熟,桔小实蝇种群动态会出现多个峰值,3~5月桔小实蝇种群高峰期主要出现在枇杷园,7~10月主要出现在石榴园、小红枣园和水蜜桃园。对桔小实蝇在蒙自种群动态的调查,能够为下一步防治措施的制定做好准备。     

典型喀斯特洼地植被恢复过程中土壤碳氮储量动态及其对极端内涝灾害的响应

西南喀斯特地区是我国主要的生态脆弱区之一,石漠化严重,旱涝灾害频发。植被恢复是提升脆弱生态系统土壤碳氮固持的有效方式,但该区不同植被恢复方式土壤碳氮动态监测的研究还很缺乏。本研究以典型喀斯特峰丛洼地为对象,选取人工林、牧草地、人工林+牧草地、撂荒地自然恢复4种最主要的植被恢复方式为研究对象,以耕地作为对照,对比分析退耕前(2004年)、退耕10年(2014年)和13年后(2017年)土壤碳氮储量动态变化特征。其中2004—2014年研究区未发生极端内涝灾害, 2014—2017年连续发生2次极端内涝灾害事件。研究结果表明,退耕10年后, 4种恢复方式下土壤有机碳(SOC)储量均显著增加,但退耕13年后,除撂荒地SOC持续增加外,其他3种恢复方式下SOC表现出下降趋势。植被恢复后土壤全氮(TN)储量提升相对缓慢,退耕10年仅牧草地显著增加,退耕13年后人工林+牧草和撂荒地TN增加,且撂荒地在退耕后呈持续增加趋势。相关性分析结果表明,土壤交换性Ca~(2+)与SOC、TN均呈显著正相关关系,且与2014年相比, 2017年不同植物恢复方式下土壤交换性Ca~(2+)均显著下降,这可能与研究区2015年和2016年连续内涝灾害有关。以上结果说明,不同恢复方式均能显著提升喀斯特地区土壤碳氮固持,并以自然恢复最佳,其生态系统能有效抵御极端气候灾害带来的负面影响。     

红枣质量安全追溯对策研究

新疆具有光照时间长、昼夜温差大、年降水量少等优良的自然条件,为红枣的生长提供了卓越的环境,促使新疆成为最优区域的红枣生产地。在中国加入WTO后,红枣生产和加工的经济价值收益可观,在世界贸易中占绝对的主导地位,使得红枣产业的发展突飞猛进,面积迅速增加,成为又一支柱性产业。但是近年来一些有关红枣表面残留农药、加工过程中食品添加剂使用过量等质量安全问题频频出现,为了解决红枣中存在的质量安全问题,并且使新疆的红枣产业能够更健康、安全、持续稳定的发展,做出了相应的分析并提出了解决措施。     

Relative abundance and damage of some insect pests of wheat under different tillage practices in rice–wheat cropping in India

Tillage changes the physical and chemical properties of soil and can also inhibit or enhance useful and harmful fauna. In agriculture, different tillage technologies are being tried to enhance crop productivity, but little concrete information seems to exist on their effects on pest abundance and damage. To address this lack of information, sowing of wheat was investigated under different tillage systems. In order to monitor pest abundance and damage in altered tillage systems, the present studies on the relative abundance and damage due to insect pests viz. pink stem borer (PSB, Sesamia inferens Walker), termites (Microtermes obesi Holmgren and Odontotermes obesus Rambur) and root aphid (Rhopalosiphum rufiabdominalis Sasaki) were undertaken in a rice–wheat cropping system during 2010–11 and 2011–12. Pest abundance and damage was monitored in four tillage systems i.e. conventional tillage (CT), zero tillage (ZT), ZT + mulch and rotary tillage (RT) under insecticide protected and unprotected conditions. The application of insecticide did not affect root aphid incidence or termite damage. However, significant differences in PSB damage in insecticide protected (0.9%) and unprotected (1.2%) conditions were observed. The investigations demonstrated that in CT, damage by PSB (0.6%) was minimum; however termite damage (2.2%) was maximum as compared to all other tillage conditions. In ZT, PSB damage (1.4%) was maximum and root aphid incidence (3.1 aphids/tiller) was minimum in comparison to other tillage conditions. ZT + mulch resulted in inter-mediate insect pest incidence/damage; however, RT was the least effective practice which showed relatively high incidence/damage of these three insects (1.2% PSB damage, 1.9% termite damage and 5.1 aphids/tiller). The insecticide × tillage interaction indicated that insecticide application is needed only in ZT and RT for PSB management.     

The use of remote sensing to detect the consequences of erosion in gypsiferous soils

Tillage practices on sloping ground often result in unsustainable soil losses impairing soil functions such as crop productivity, water and nutrients storage, and soil organic carbon (SOC) sequestration. A sloping olive grove (10%) was planted in shallow gypsiferous soils in 2004. It was managed by minimum tillage; the most frequent management practice in central Spain. The consequences of erosion were studied in soil samples (at 0–10, 10–20, and 20–30 cm depths) by analyzing SOC, available water and gypsum content, and by detecting spectral signatures using an ASD FieldSpecPro® VIS/NIR-spectroradiometer. The Brightness index (BI), Shape index (FI), and Normalized Difference Vegetation Index (NDVI) were derived from the ASD spectral signatures and from remote sensing (Sentinel-2 image) data. The development of these young olive trees was estimated from the measured diameter of the trunks (17 ± 18 cm diameter). In 20–30 cm of the soil, the carbon stock (38 ± 18 Mg ha⁻¹) as well as the available water content (12 ± 6%) was scarce, affecting the productivity of the olive grove. The above-mentioned indices obtained from the laboratory samples and the pixels of the Sentinel-2 image were significantly (p < 0.01) correlated, with a correlation coefficient of around 0.4. The BI was related to the gypsum content and the slope of the plot. The FI was related to the carbon and water contents. The NDVI derived from the satellite image identified the influence of soil degradation on the trees and the carbon content. The spatial-temporal changes of the indices might help in tracking soil changes over time.     

牧草种子基地建设基本经验和措施初探

牧草种子基地建设是我国重大生态建设的基础性建设项目。该项目的建立,对满足生态建设和退耕还草、退牧还草的种子需要具有重要意义。通过4年多的建设和实践证明:牧草种子基地建设一定要建立在有可靠、准确、翔实的基础资料和科学、合理的设计之上。按照建设方案和遵守规章制度是项目建设的基本要求,科学的管理和经营是基地长期存在的必要条件。要根据目前种子市场,正确处理和调整好牧草种子与牧草及草产品之间的关系,采用先进的管理措施,多方位、多思路求发展,才能提高牧草种子基地的经济效益,逐步促使牧草种子基地规范化、标准化。