间种白三叶草和稻草覆盖控制丘陵茶园杂草效果

开展丘陵茶园杂草生态控制,可减少对茶园土壤水分和养分的消耗,避免使用化学除草剂。连续2年的田间试验,野外应用小样方多点采样调查茶园杂草种群数量、生物量、平均株高和茶芽密度等指标,结合实验室的茶叶内含成分分析和感官评审。结果表明:茶园共有杂草16科31属31种,春季(4月)以生长速度较慢、生物量小、株高在30cm以下的杂草为主,夏季(7月)以生长快、植株高和生物量大恶性杂草为主,秋季(9月)恶性杂草开始减少,酢浆草、白花蛇舌草等生物量小、株高矮的杂草逐渐增多;稻草覆盖处理茶园春、夏和秋季3个观测时期杂草物种丰富度(S)、多样性(H)、均匀度(J)等指数均高于清耕对照,优势集中性指数(C)低于清耕对照;间种白三叶草处理春、夏和秋季3个观测时期杂草总数量和生物量均显著低于清耕对照,夏、秋季杂草平均株高显著低于清耕对照;稻草覆盖和间种白三叶草处理春季茶芽重和产量显著高于清耕对照,鲜叶中游离氨基酸含量高于清耕对照,茶叶感官评审得分高于清耕对照处理。这表明稻草覆盖和间种白三叶草能改变茶园杂草群落结构,有效控制杂草生长,增加茶叶产量和改善茶叶品质。     

山地茶园不同控草技术效果比较

以山地茶园杂草自然生长为对照,设间种白三叶草、五节芒茎秆覆盖、防草布覆盖3种不同措施控草,研究不同控草措施的效果.结果表明:五节芒茎秆覆盖处理效果最好,防草布覆盖处理效果较好,间种三叶草处理有一定控草效果.综合比较,山地茶园杂草防控效果为五节芒茎秆覆盖>防草布覆盖>间种白三叶草.五节芒茎秆覆盖处理对山地茶园杂草防控效果...     

不同生态管理措施对丘陵茶园土壤微生物生物量和微生物数量的影响

研究了间种三叶草、稻草覆盖与有机无机肥配施等不同生态管理措施对丘陵茶园土壤微生物生物量和微生物类群数量的影响,结果表明:与CK(NPK肥+清耕)相比,饼肥+PK+清耕、NPK肥+稻草覆盖、饼肥+PK+稻草覆盖、NPK肥+间作三叶草、饼肥+PK+间作三叶草处理微生物量C、N、P均有提高,NPK肥+间作三叶草、饼肥+PK+间作三叶草处理中细菌数量较高,NPK肥+稻草覆盖、饼肥+PK+稻草覆盖处理土壤放线菌数量较高,但各处理间真菌数量变幅不大。总的来说,NPK肥+稻草覆盖与饼肥+PK+间作三叶草处理促进土壤微生物生长的效果最为明显。相关分析表明,土壤微生物量C与有机质、全N和速效N相关性优于其他微生物活性指标,适宜作为生态茶园土壤健康评价的敏感因子。     

覆盖和间作对亚热带红壤茶园土壤磷营养的影响

为了探索提高土壤磷素营养的方法,以湖南省长沙县百里茶廊的湘丰茶厂东西山茶园为研究对象,采用田间试验和室内分析方法,研究了稻草覆盖和间作白三叶草对亚热带红壤茶园土壤磷素营养特征的影响。结果表明,不同管理措施对土壤磷素营养有明显影响。稻草覆盖可增加土壤全磷含量,提高土壤磷库;间作白三叶草主要影响土壤中磷形态的转化,使有效磷含量提高,但对土壤磷库无明显影响;CK则导致磷库耗竭,土壤磷库下降10．3％。与CK相比,间作白三叶草（绿肥）有利于提高土壤微生物量碳（MB—C）和微生物量磷（MB-P）,而稻草覆盖处理可以减轻MB—C和MB—P波动,保持MB—C和MB—P的稳定。稻草覆盖和间作白三叶草均有利于提高土壤微生物量,且间作白三叶草处理在白三叶草生长旺季土壤微生物量提高得更多。MB—C／MB—P值表明,稻草覆盖和间作白三叶草均可促进土壤磷素活化,提高土壤速效磷含量。间作白三叶草对土壤速效磷含量提高最多,说明间作白三叶草处理对土壤速效磷有重要影响。     

覆盖对山地幼龄茶园杂草多样性及茶苗生长的影响

为研究覆盖处理对山地幼龄茶园杂草多样性及茶苗生长的影响,构建山地幼龄茶园杂草生态防控模式,采用单因素对比试验,设置3个覆盖处理和1个祼地对照,分析比较其土壤温度、杂草群落结构、茶苗生长、控草成本的差异.结果:1)覆盖无纺布处理和覆盖地膜处理,有利于提高冬季土壤温度;显著减少春夏季杂草发生,杂草萌发量从低到高依次为地膜<...     

六堡茶茶园间种黑麦草抑制杂草效果试验初报

为减少茶园草害,解决有机茶园人工除草难问题,通过在六堡茶茶园行间间种黑麦草,研究黑麦草对杂草生长的影响,同时设置清耕对照,采用小样方调查法,调查茶园杂草种群数量、生物量、株高等指标。结果表明:1)在黑麦草组中调查到7个科12种杂草,对照组共调查到13个科22种杂草,黑麦草组比对照组杂草少6个科10种杂草。2)从杂草密度、株高、盖度、干重、发生频率比较,黑麦草能有效抑制茶行间杂草的生长。     

3种典型生物措施对亚热带红壤丘陵茶园季节性干旱的防御效果

在采集湖南省长沙县1960～2001年气象资料的基础上．探讨了我国亚热带红壤丘陵茶园夏季高温干旱和秋季持续干旱的发生规律，并以常规管理茶园为对照，通过2001～2004年连续4年大田对比试验，分析了杉树高层间作、白三叶草低层间种和稻草覆盖3种典型生物措施对茶园季节性干旱的防御效果，结果发现，3种生物措施明显减少了茶园全年0～20cm土层土壤含水量≤15％，≤12％，≤10％的出现频率，在夏季高温干旱和秋季持续干旱时期均提高了茶园土壤含水量，有效地延缓和缩短了干旱时间，缓解了旱情，显著增加了夏秋茶产量，改善了夏秋茶品质。     

连续5年施菜籽饼肥和稻草覆盖对茶园土壤生态系统的影响

在长沙县百里茶廊连续进行5年的定位试验,研究施菜籽饼肥结合稻草覆盖对丘陵茶园土壤生态系统的影响。结果表明,施菜籽饼肥加稻草覆盖处理(TI)茶园土壤pH、有机质含量、全氮含量、有效磷含量均显著高于纯施化肥处理(T3),0～40cm土层土壤容重显著低于T3处理,0～60cm土层土壤水分含量、0～20cm土层蚯蚓数量和生物量、氨基化细菌、好气性自生固氮菌、嫌气性自生固氮菌、放线菌、真菌和细菌等微生物数量均显著高于T3处理。施菜籽饼肥结合稻草覆盖可显著改善丘陵茶园土壤生态功能,菜籽饼化肥配施结合稻草覆盖(T2)也一定程度改善了土壤生态系统,长期不施肥使茶园土壤养分贮存量全面下降。     

盛夏覆盖对幼龄茶园土壤温湿度和杂草生长的影响

江南茶区夏季高温少雨,新建茶园易受旱热草害,从而影响茶苗成活率和生长。为了探讨不同覆盖材料在幼龄茶园中保湿、降温、抑制杂草的效果,采用单因素对比试验,设置4个覆盖处理,1个裸地对照,在杭州盛夏高温季节对各处理土壤温度和湿度变化及控草效果进行了比较研究。结果表明:夏季晴热高温季节,黑膜、无纺布和覆草处理均可显著降低土壤温度,减小温度日较差。持续晴热7天和14天时,黑膜和覆草处理土壤含水量显著高于对照组。覆盖均能极显著抑制茶行杂草的生长,其中黑膜和无纺布处理的杂草生长量极显著低于白膜和覆草处理。所有覆盖处理都能极显著降低拨草人工费,最高效的黑膜覆盖处理可以节约8 550元/hm~2,所用工时只有对照组的24.95%,扣除覆盖成本投入,每公顷可以节约6 370元。综合比较各种覆盖材料在降低土壤温度、提高土壤含水量、控制杂草生长及降低除草成本方面的效果,发现黑膜处理效果最好,其次是无纺布和覆草处理。因此,新茶园夏季覆盖材料推荐使用黑地膜、覆草和无纺布。     

稻草覆盖和草篱对红壤缓坡旱地水土流失及作物产量的影响

以红壤缓坡旱地为对象,研究稻草覆盖和香根草篱对水土流失及花生产量的影响。2011—2012两年的研究结果表明,不同处理产生的径流量大小排序为:对照稻草覆盖、草篱草篱+稻草覆盖。水土保持效果最好的是草篱+稻草覆盖处理,与对照相比,径流量显著减少了47.1%~79.8%(P0.05),土壤侵蚀量显著减少了79.2%~99.5%(P0.05)。2011—2012年作物产量最高的分别是稻草覆盖和草篱+稻草覆盖处理,与对照相比,这两种处理可分别增产26.6%~50.9%、15.5%~37.7%(P0.05)。因此稻草覆盖、草篱+稻草覆盖结合是红壤缓坡旱地水土保持的有效措施。     

浮萍覆盖对稻田杂草群落组成及多样性的影响

在农业可持续发展的背景下,稻田杂草防控需要兼顾生物多样性的保护。为了解浮萍覆盖对稻田杂草群落组成及物种多样性的影响,运用群落生态学的方法,研究了多根紫萍覆盖(SP)、少根紫萍覆盖(LP)和不投放浮萍(CK)3种处理下稻田杂草发生量和群落多样性在水稻4个生育期(分蘖期、孕穗期、扬花期和成熟期)的动态变化,并对水稻产量进行分析。结果表明:SP和LP处理在前两生育期分别比CK显著降低杂草密度60.3%～75.8%和81.1%～90.4%,在整个水稻生育期能分别降低杂草鲜重生物量48.0%以上和81.3%以上,杂草群落中阔叶类杂草比例明显下降。不同处理下,稻田最主要杂草类别均是莎草科杂草;不同处理的杂草群落中重要杂草的种类和相对重要程度都有较大差异,SP和LP处理重要值较高的杂草均为莎草科的萤蔺和碎米莎草,CK处理重要值较高的杂草则为阔叶类的鸭舌草;在多数生育期,两种浮萍覆盖下的杂草群落的Margalef丰富度指数、Shannon-Wiener多样性指数和Simpson优势度指数均与CK无显著差异。SP和LP处理水稻的每穗粒数和穗重均有不同程度显著提高, SP处理的水稻产量显著提高28.0%。综合上述分析,稻田投放初始覆盖面积70.0%的多根紫萍和少根紫萍都能在降低稻田杂草密度和生物量的同时维持杂草群落的多样性,且多根紫萍覆盖能促进水稻产量增长,对保护稻田生物多样性和促进农业可持续发展有重要意义。     

覆盖与间作对亚热带丘陵幼龄茶园土壤环境和生产的影响

以常规管理茶园(清耕茶园)为对照，通过连续4a大田对比试验，研究了稻草覆盖与间作白三叶草对亚热带丘陵幼龄茶园土壤环境及茶叶品质、产量的影响。研究结果表明：两种生物措施均降低了土壤容重，增加了土壤有机质含量，影响了土壤养分的供应状况，提高了土壤关键层次(0～20 cm)和关键时期(4～6月)的水分含量，获得了不同观察时刻、不同深度土壤温度的多种调控效果，延缓和缩短了高温和干旱时间，促进了茶树生长，改善了茶叶品质，显著增加了茶叶产量，其名优绿茶酚氨比分别下降了0.68%和28.14%，产量提高了26.19%和32.65%，间作白三叶草的效果更好。     

Effect of soil tillage and weed control methods on weed biomass and yield of lentil (Lens culinaris Medic.)

Abstract

The study was carried out in dryfarming areas in Ankara, Turkey, over 2 years (2001 – 2002 and 2002 – 2003). The objective was to determine different soil tillage and weed control methods on weed biomass and yield components, yield of lentil (Lens culinaris). This study compared the effects of two tillage systems (shallow minimum tillage and traditional tillage) and three weed control methods (weedy check, hand weeding and herbicide) on weed biomass, growth characteristics, seed yield and some yield components of lentil. Significant differences were found among weed control methods for weed biomass and yield parameters of lentil. Tillage systems had no significant effect on weed biomass or yield of lentil. The highest yield and lowest weed biomass was found in the hand-weeded treatment compared to the other weed control methods. Results of this research indicate that weeds are a main constraint for lentil growing under dryland conditions. Grain yield of lentil was reduced more than 60% due to uncontrolled weeds.     

耕作方式对新垦沙地农田杂草群落结构的影响

通过田间调查的方式,研究了黑河中游边缘绿洲新垦沙地农田杂草分布状况,并对不同耕作方式下农田杂草群落结构特征进行了分析。调查中共记录杂草16种,隶属10科。新垦沙地农田杂草群落基本组成为藜(Chenopodium album)+牛筋草(Eleusineindica)+狗尾草(Setaria viridis)+反枝苋(Amaranthus retroflexus)。与当地传统的地膜覆盖、秋耕和玉米连作耕作方式相比,秸秆覆盖、减少秋耕和玉米-大豆轮作均可增加农田杂草物种丰富度、多样性指数和群落优势度(P0.05)。与当地传统耕作方式相比,秸秆覆盖可增加杂草群落中牛筋草优势度比,降低藜和反枝苋优势度比;减少秋耕可增加狗尾草、反枝苋、灰绿藜(C.glaucum)和米瓦罐(Silene conoidea)优势度比,降低牛筋草优势度比;玉米-大豆轮作可增加米瓦罐优势度比。不同耕作方式对偶见种杂草在田间的分布和组成影响不明显。可以看出,新垦沙地农田杂草物种较少,群落组成单一;不同耕作方式对新垦沙地农田杂草物种多样性和群落结构组成有明显影响,进一步深入研究对沙地农田杂草合理防除具有重要的指导意义。     

规模化稻鸭生态种养对稻田杂草群落组成及物种多样性的影响

为探索规模稻鸭生态种养稻田杂草群落的变化动态,运用植物群落生态的方法研究了规模稻鸭生态种养、常规稻鸭生态种养和水稻单一种植稻田杂草的群落变化特点及控草效果。结果表明:规模稻鸭生态种养杂草密度显著降低,与水稻单一种植比较防效为94%;水稻分蘖到孕穗期稻田杂草主要由看麦娘(Alopecuruspratensis)、稗草(Echinochhloa crausgalli)、狗牙根(Cynodon dactylon)、水花生(Alternanthera philoxeroides)、鸭舌草(Mouochoria vaginalis)、水竹叶(Murdannia triquetra)和鳢肠(Eclipta prostrata)组成,抽穗期到成熟期主要由水花生、稗草、狗牙根和水竹叶组成。研究还表明,规模稻鸭生态种养水稻分蘖期物种丰富度、Simpon指数、Shannon-Wiener指数略高于水稻单一种植,Pielou指数低于水稻单一种植;孕穗期到成熟期物种丰富度、Simpon指数、Shannon-Wiener指数低于水稻单一种植,Pielou指数显著高于水稻单一种植。水稻全生育期规模稻鸭生态种养与常规稻鸭生态种养比较稻田杂草密度、杂草生物量和多样性指数差异不显著,但杂草生物多样性指数略有提高。说明规模稻鸭生态种养显著改变稻田杂草的群落结构和组成,可抑制杂草发生危害,达到有效控草目的。     

Effect of reduced tillage on weeds and soil organisms in winter wheat and summer maize cropping on Humic Andosols in Central Japan

Although reduced tillage (RT) may preserve soil biota and improve the productivity and sustainability of arable lands in temperate regions, the extension of RT is limited by difficulties in controlling weeds. We studied the effect of RT without herbicide application on weed communities and soil biota in a 1-year 2-crop rotation system with winter wheat (Triticum aestivum L.) and maize (Zea mays L.) on Andosols in Japan. RT of the surface 3 cm and conventional moldboard plowing (CT) were conducted before seeding twice per year. For the first 3 years, from autumn 1997 to spring 2000, one field was managed with RT and another with CT. For the second 3 years, from autumn 2000 to spring 2003, RT and CT were conducted in two replicated plots in each field. Weed communities and soil biota were studied in the last 2 years. Dominant weed species in winter wheat cropping were Italian ryegrass (Lolium multiflorum Lam.) in 2002 and common vetch (Vicia angustifolia L.) in 2003, and their biomass was high where RT or CT was continuously conducted. Switching of tillage methods, from RT to CT or vice versa, reduced the biomass of winter weeds. In summer maize cropping, several annual and perennial weed species tended to increase under RT in the second 3 years. However, redroot pigweed (Amaranthus retroflexus L.), the most dominant weed in 2002 and 2003, responded to tillage inconsistently and its biomass was not always increased by RT. Species diversity of winter weeds was decreased by CT conducted in the first 3 years, and that of summer weeds was decreased by CT conducted in the second 3 years. The seedbank in the 0–10-cm soil layer under recent RT was large (7200–16 300 seeds m⁻²) compared with that under CT (2900–7300 seeds m⁻²). The microbial substrate-induced respiration (SIR) and the population densities of nematodes and mites were higher under RT in the second 3 years and were not affected by previous tillage practices. Both were highly correlated with soil total nitrogen. The positive effect of RT on these soil organisms was primarily attributable to the accumulation of organic matter in soil, but not to plant cover as a result of incomplete weed control by RT. Occasional adoption of RT in current CT systems may be effective at enriching soil organisms with little risk of weed infestation.     

Effect of tillage intensity on weed infestation in organic farming

Conservation tillage is not yet widely accepted by organic farmers because inversion tillage is considered to be necessary for weed control. Three long-term experiments were established with combinations of reduced and conventional plough tillage and stubble tillage to determine weed infestation levels in organic farming, i.e. herbicide application being excluded. Experiment 1 (with very low stocking density of perennial weeds) showed that in presence of primary tillage by mouldboard ploughing the number of annual weeds was nearly unaffected by the mode of stubble tillage. In experiment 2, however, with Canada thistle (Cirsium arvense) being artificially established, thistle density was significantly affected by stubble tillage and by a perennial grass–clover forage crop. Experiment 3 combined two levels of stubble tillage (skimmer plough, no stubble tillage = control) with four implements of primary tillage in the order of decreasing operation depth (deep mouldboard plough, double-layer plough, shallow mouldboard plough or chisel plough). Primary tillage by chisel plough resulted in significantly highest annual weed density compared to all other treatments. The natural C. arvense infestation in experiment 3 showed highest shoot density in the “skimmer plough/chisel plough” treatment compared to the lowest infestation in the “skimmer plough/double-layer plough” treatment. The poor capacity of the chisel plough for weed control was also reflected by the soil seed bank (5500 m⁻² C. arvense seeds for chisel plough, <300 seeds for all other primary tillage). A reduced operation depth of the mouldboard plough (“shallow mouldboard plough”) seemed to have an insufficient effect in controlling C. arvense infestation as well. Stubble tillage by the skimmer plough in addition to nearly any primary tillage operation largely reduced both annual weeds and thistle shoots. Most effective in controlling C. arvense was also a biennial grass–clover mixture as part of the crop rotation.Double-layer ploughing is a compromise between soil inversion and soil loosening/cutting and can be regarded as a step towards conservation tillage. In terms of controlling annual weeds and C. arvense, the double-layer plough was not inferior to a deep mouldboard plough and seems to be suitable for weed control in organic farming. Tilling the stubble shallowly after harvest can support weed control in organic farming remarkably, particularly in reducing C. arvense. If no noxious, perennial weeds occur and primary tillage is done by soil inversion, an omission of stubble tillage can be taken into consideration.     

Residue cover,soil structure,weed infestation and spring cereal yields as affected by tillage and straw management on three soils in Norway

Four field trials (spring wheat and oats) were conducted (one on clay soil, one on loam soil and two on silt soil) for three years in important cereal growing districts, to investigate the influence of tillage regimes (ploughing versus reduced tillage in either autumn or spring) and straw management (removed and retained) on plant residue amounts, weed populations, soil structural parameters and cereal yields. The effect of tillage on soil structure varied, mainly due to the short trial period. In general, the amount of small soil aggregates increased with tillage intensity. Reduced soil tillage, and in some cases spring ploughing, gave significantly higher aggregate stability than autumn ploughing, thus providing protection against erosion. However, decreasing tillage intensity increased the amounts of weeds, particularly of Poa annua on silt soil. Straw treatment only slightly affected yields, while effects of tillage varied between both year and location. Reduced tillage, compared to ploughing, gave only small yield differences on loam soil, while it was superior on clay soil and inferior on silt soil. Our results suggest that shallow spring ploughing is a good alternative to autumn ploughing, since it gave comparable yields, better protection against erosion and was nearly as effective against weeds.     

Conservation tillage and mulching effects on the adaptive capacity of direct-seeded upland rice (Oryza sativa L.) to alleviate weed and moisture stresses in the North Eastern Himalayan Region of India

A field experiment was conducted to study the effects of tillage and mulch on weed growth, soil moisture storage, productivity and profitability of upland rice during 2012–2013 at Lembucherra, India. Tillage treatments included CT-RI: conventional tillage with 100% residue incorporation and NT-RR: no-till with 100% residue retention. Mulches included rice straw (SM), Gliricidia (GM), brown manuring (BM) and none (NM). CT-RI registered the highest total weed density (89–168 weeds m^?2) and biomass (9.6–183 g dry weight m^?2) than those for the NT-RR (75–161 weed m^?2 and 8–155 g dry weight m^?2). In addition, NT-RR stored (122–172 mm) more soil moisture (0–40 cm soil depth) in comparison with that for the CT-RI treatment (110–161 mm) during crop growing season. Tillage treatments did not have the significant effect on yields. NT-RR reduced the cost of cultivation by 31.5% compared with that for the CT-RI. Thus, the net returns under NT-RR were more than those for the CT-RI. The BM recorded the lowest weed biomass and density as compared to that under other mulches. Therefore, cultivation of upland rice using NT along with BM mulching enhanced productivity and profitability of rice cultivation in India.