春播紫花苜蓿苗期杂草的化学防治研究

紫花苜蓿(Medicago sativa L.)苗期杂草危害严重,显著影响建植,为此采用单因素完全随机区组设计的方法,探究7种除草处理对苜蓿产量、品质和杂草防除效果的影响。结果表明:2,4-DB、苯达松及其混用组合处理可有效防除阔叶类杂草,株防效在75.80%～90.65%之间;高效盖草能、精喹禾灵、烯草酮可有效防除单子叶杂草,株防效高于71.10%。喷施2,4-DB会使苜蓿的总产量减少64%以上;喷施苯达松+高效盖草能、苯达松+精喹禾灵、高效盖草均能显著地提高第2茬的产量,苜蓿总产量分别提高45.60%,45.28%和43.06%。综合考虑除草剂的安全性和除杂增产效果等方面,以苯达松+高效盖草能和苯达松+精喹禾灵2种除草处理的效果较好,可在苜蓿生产田推广利用。     

化学除草剂对越冬之星苜蓿杂草防除效果的试验

为探讨研究除草剂对越冬之星苜蓿苗期的杂草防除效果，以期筛选出适宜的除草剂品种，笔者进行了化学除草剂对越冬之星苜蓿的杂草防除试验，并对苜蓿株高、产量及杂草量作了综合调查与分析。结果表明，高效盖草能、精禾草克、精稳杀得、拿捕净对禾本科杂草的防效为100％，5％苜草净在杂草株龄较大的情况下综合表现较好。苜蓿无药害的除草剂品种推荐5％苜草净在杂草株龄较大的情况下喷雾。     

苜蓿田间杂草综合防除的研究

根据苜蓿的生长规律以及田间杂草的危害特点，提出了苜蓿田间杂草综合防除的基本措施。播前精细整地、早秋适时播种、窄行条播、间播多年生禾本科牧草以及刈割期及时清除杂草，能有效地防除苜蓿田间杂草。     

四川国际高尔夫球场草坪杂草及其化学防除研究

1997－1999年的调查结果表明：四川国际高尔夫球场草坪杂草有19科40种，其中数量最多，危害较严重的杂草5种：黄花酢浆草、天胡荽、香附子、水蜈蚣和马唐，占所有杂草数量的95％以上，化学防除试验结果表明：用百草敌1．0g/10m^2 2,4-D0.2g/10m^2可有效防除草花酢浆草等阔叶杂草；用苯达松1．0g/10m^2＋2甲4氯1．5g/10m^2可有效防除香附子等莎草科杂草，用Dithiopyr0.12-0.24g/10m^2可有效防除马唐。     

苜蓿草地杂草防除技术探讨

本文在研究苜蓿的生长规律以及田间杂草的植物学与生物学特点的基础上，提出了苜蓿草地田间杂草综合防除的基本措施。结果表明，播前精细整地，早秋适时播种，窄行条播，间播多年生禾草以及刈割期及时清除杂草，能有效地防除苜蓿田间杂草。     

十四种化学除草剂对沧州地区苜蓿地杂草防效试验

选用14种除草剂对沧州地区苜蓿(Medicago sativa)地苗期的杂草进行了防除试验。对苜蓿株高,产量及杂草量的综合调查分析结果表明,高效盖草能、精禾草克、精稳杀得、拿捕净对禾本科杂草的防效为100%,苜蓿保系列各剂型在杂草株龄较大的情况下综合表现较好,其中苜蓿保2%EC将杂草率从80.6%(CK)降到了36.5%,苜蓿增产40.6%。沧州地区春播苜蓿幼苗期单独使用禾本科除草剂或阔叶草除草剂效果不理想。     

移栽马蹄金草坪杂草的化学防除

马蹄金草坪因其外观美丽,性能优良,被广泛应用。由于多种因素的影响,特别是移栽马蹄金草坪中杂草的危害,影响了马蹄金草坪质量。前人曾用2-甲四氯、稳杀得、苯达松、盖草能等化学药剂进行防除,取得了一定的成效,但对马蹄金草坪存在不同程度的药害。为此,挑选除杂效果较好的苯达松与盖草能进行研究,找出了较理想的用药浓度。     

云南昆明草坪杂草化学防除效果研究

在昆明市春城高尔夫球场开展了除草剂防除草坪杂草的试验,以期为南方地区草坪杂草的化学防除提供科学依据.结果表明:用百草敌0.1 g/m2 二甲四氯钠0.02 g/m2和百草敌0.08 g/m2 使它隆0.06 g/m2能有效防除红花酢浆草Oxalis corymbosaca等阔叶杂草,用苯达松0.1 g/m2与都尔乳液0.2 g/m2和苯达松0.1 g/m2与二甲四氯钠0.15 g/m2可有效防除香附子Cyperus rotundus和水蜈蚣Kyllinga brevifolia等莎草科杂草,用氟硫草定0.024 g/m2可有效防除马唐Digitaria sanguinaliss.选择混合药剂的防除方式,苯达松0.1 g/m2与都尔乳液0.2 g/m2具有最好的防除效果.     

沟叶结缕草草坪杂草化学防治研究

采用苯达松、2,4-D丁酯、高效盖草能(10％乳油)3种除草剂对沟叶结缕草草坪进行了杂草化学防治研究。结果表明,苯达松(25％水剂)每15 kg水可加至80 ml左右,2,4-D丁酯(72％乳油)每15 kg水可加至25 ml,高效盖草能(10％乳油)每15 kg水可加至10-15 ml,每667m2控制用水25-30 kg可取得较好效果。但高温季节除草剂容易对草坪产生药害,施用时应在杂草幼苗期进行,并降低药剂浓度,以提高对草坪的安全性。     

冷季型草坪杂草化学防除技术研究

1997年开始进行冷季型草坪杂草化学除技术研究，阔叶杂草在2－4叶期和72％的2，4－D丁酯乳油防，防除效果可达92．4％，禾本科杂草用拉索，扑草净，乙草胺，氟乐灵进行播前诱杀防除，防除效果分别可达84．6％、65．9％，51．8％和45．0％。     

扎兰屯市紫花苜蓿田杂草种类调查与防治

2007年选择扎兰屯市人工种植的紫花菖蓿田,从春季萌发后开始定点定期调查田间杂草的种类及发生危害规律,通过调查明确了扎兰屯市紫花苜蓿田杂草共计有14种,分属于8科,13属;当地的优势杂草及发生特点,并且制定出了杂草的综合防治技术,对指导苜蓿田的除草具有实用价值。     

不同土地利用方式对苜蓿茬地土壤微生物生物量碳、氮的影响

在甘肃庆阳黄土高原,用熏蒸法研究了土地利用方式对紫花苜蓿Medicago sativa后茬土壤微生物生物量碳、氮的影响.结果表明:4龄苜蓿后茬种植小麦Triticum aestivum 2年后,0～5 cm土壤层微生物生物量碳比苜蓿生长地降低70 mg/kg,休闲地仅为苜蓿生长地的40%,施氮肥对土壤微生物生物量碳无显著影响(P＞0.05);苜蓿后茬连续种植小麦2年后,0～5 cm土壤层微生物生物量氮比苜蓿生长地下降28%,而休闲2年后比苜蓿生长地减少69%,施氮肥对微生物生物量氮无显著影响;苜蓿生长地土壤微生物商为4.2%,后茬休闲后则下降至2.7 %.土壤微生物生物量碳、氮可灵敏反映苜蓿后茬地土壤质量的变化.     

陇东黄土高原冬小麦地土壤杂草种子库初探

土壤杂草种子库是农田发生杂草危害的主要根源,为了明确不同小气候条件和栽培管理措施对杂草种子库特征的影响,对庆阳市和天水市冬小麦地土壤种子库进行了比较研究。结果表明：庆阳市冬小麦土壤杂草种子有9科20种,其中田边、田中杂草量分别为2 520、1 964 株/m2,稗草Echinochloa crusgalli数量较大,分别占47.54%和30.50%;天水市冬小麦土壤杂草种子有10科13种,其中田边、田中总出草数分别为3 873、3 506 株/m2,小蓟Breea arvensis、蚤缀Arenaria serpyllifolia数量较大,在田边、田中分别占34.68%、28.27%和32.29%、32.63%。两地田边杂草发生总数均高于田中发生总数。其中,稗草、狗尾草Setaria viridis、灰绿藜Chenopodium glaucum是两地区农田的主要杂草和当前防除的重点,稗草和小蓟、蚤缀分别是庆阳市和天水市冬小麦地的优势种。通过分析两地冬小麦地土壤杂草种子库发生原因,提出了麦田杂草的防除策略。     

温度和湿度对紫花苜蓿土壤氮矿化的影响

为确定温度和水分对土壤氮矿化特征的影响,以取自甘肃庆阳黄土高原4年龄(4a)和8年龄(8a)紫花苜蓿草地0~10cm土壤为对象,在不同的温度(5,15和25℃)和水分(30%,50%和70%田间持水量)组合下进行了室内培养。结果表明温度是影响黄土高原紫花苜蓿草地土壤净氮矿化速率的主效因素,培养14d后净硝化率和净矿化率最大值均出现在25℃/70FC下,分别为0.481μg/(g·d)(4a)和0.942μg/(g·d)(8a),0.293μg/(g·d)(4a)和0.632μg/(g·d)(8a);在5℃/30FC下4a土壤的净氮固持率最大,为0.232μg/(g·d),8a土壤则在5℃/70FC下净氮固持率最大,为0.127μg/(g·d);8a苜蓿土壤培养后微生物碳含量显著高于4a苜蓿土壤,在15℃/50FC的组合下8a土壤是4a的1.44倍。土壤有机质含量不同是导致2个年龄苜蓿土壤净硝化率、净矿化率和微生物生物量碳差异的主要原因。     

我国草坪杂草防除研究进展

根据国内文献报道 ,介绍了国内草坪杂草种类调查以及杂草防除的研究进展。草坪杂草防除的难点是禾本科杂草。用啶嘧黄隆等除草剂可有效地防除禾本科杂草。 2 ,4—D丁酯乳油等多种选择性除草剂可以防除阔叶杂草。草坪杂草的生物防治方面也有很大的进展 ,可以用盾负泥虫等天敌控制杂草的危害。并且已经提出了草坪杂草综合防治的概念     

优质高产奶牛高效全混合饲料配方筛选试验

中国荷斯坦奶牛60头饲喂4种不同紫花苜蓿干草配比、不同精粗比的日粮，以研究日粮配方对奶牛产奶量、乳脂率、经济收益的影响。试验结果说明，大比例紫花苜蓿干草日粮（紫花苜蓿占24％DM）乳脂率显著（P〈0．05）或极显著提高（P〈0．01）；日粮营养水平提高，产奶量提高（P〈0．05；P〈0．01）；最佳经济效益日粮为含大比例紫花苜蓿，营养水平较低的日粮（P〈0．01）；在大的精粗比例下，紫花苜蓿干草不是日粮成本的限制因素，而青贮饲料配比为日粮成本的限制因素。只有合理安排精粗比例，适当使用紫花苜蓿干草，可提高奶牛饲养经济效益。     

高产奶牛高效全混合饲料配方筛选试验

中国荷斯坦奶牛60头饲喂4种不同紫花苜蓿干草配比、不同精粗比的日粮,以研究日粮配方对奶牛产奶量、乳脂率、经济收益的影响.试验结果说明,大比例紫花苜蓿干草日粮（紫花苜蓿为24%DM）乳脂率显著（P＜0.05）或极显著提高（P＜0.01）;日粮营养水平提高,产奶量提高（P＜0.05 P＜0.01）;最佳经济效益日粮为含大比例紫花苜蓿,营养水平较低的日粮（P＜0.01）;在大的精粗比例下,紫花苜蓿干草不是日粮成本的限制因素,而青贮饲料配比为日粮成本的限制因素.合理安排精粗比例,适当使用紫花苜蓿干草,可提高奶牛饲养经济效益.     

Milk production performance of Friesian-Holstein cows fed diets containing Medicago sativa, Centrosema pubescens, or groundnut haulms (Arachis hypogaea)

To investigate the effect of feeding dairy cows diets containing lucerne hay, centrosema hay, and groundnut haulms (crop residue) on dry matter intake (DMI), milk yield, and milk composition, nine multiparous Friesian-Holstein cows in their mid-lactation stage were used in a 3?×?3 crossover design replicated three times. Dairy cows fed lucerne hay had significantly (p?<?0.001) higher DMI than dairy cows fed centrosema hay. DMI for cows fed groundnut haulms and lucerne hay was not significantly different. Daily milk yield for dairy cows fed diet containing lucerne hay was significantly (p?<?0.01) higher than that for dairy cows fed diets containing groundnut haulms or centrosema hay. Milk composition and body condition scores of the cows were not significantly affected by either lucerne hay, groundnut haulms, or centrosema hay. Overall, the results in this study indicated that feeding dairy cows diets containing lucerne hay increased milk yield.     

Studies on the use of lucerne silage source for high-milk-producing dairy cows

Studies on the use of lucerne silage as a forage source for high-yielding dairy cows. It was the main objective of this study to investigate effects of lucerne silage inclusion in maize silage-based rations on dry matter intake, milk yield and metabolic parameters of high yielding dairy cows. Three total mixed rations (TMR) were used. They contained as the main forage source on a dry matter basis 41.5% maize silage and 12% grass silage (ration maize) or 18% maize silage and 29% of either grass silage (ration grass) or lucerne silage (ration lucerne). Organic matter digestibility, determined with wether sheep, was 77 and 65% for the grass and the lucerne silage, respectively. Each TMR was fed to 4 wether sheep to determine crude nutrient digestibilities. The content of net energy for lactation (NEL), as calculated from digestible crude nutrients, was (MJ/kg dry matter (DM)): 7.1 (maize), 7.2 (grass) and 6.8 (lucerne). Based on the results of a chemical fractionation of crude protein it was calculated that the content of utilisable crude protein (nXP) was not below 167 g/kg DM and that the N balance in the rumen was not negative for all 3 TMR. The TMR were fed for 169 days to at least 28 dairy cows per treatment which were in their first half of lactation. Feed intake, milk performance data and physiological indicators were measured for each individual cow. The DM intake was significantly higher in treatment lucerne (23.2 kg/d) than in treatments grass (21.2 kg/d) and maize (22.6 kg/d). Daily intakes of NEL and nXP were significantly lower in treatment grass than in the other two treatments. Milk yield was significantly higher in treatment maize (41.7 kg/d) than in treatments grass (37.3 kg/d) and lucerne (38.5 kg/d). This was associated with a significantly lower milk fat content in treatment maize (3.5%) in comparison with the other two treatments (3.9% each). Milk protein content was unaffected by treatment (3.4% on average). Similarly, the acetone content of milk was not significantly different between treatments. The beta-hydroxybutyrate content of the deproteinized blood was significantly higher in treatment lucerne at start of lactation, but this difference disappeared in subsequent parts of the experimental period. Measurements of back fat thickness indicated mobilisation and retention of energy by cows during the experimental period to be similar in all treatments. It is concluded that lucerne silage is a suitable forage source for high yielding dairy cows in spite of its low digestibility.