"饲用玉米-黑麦草"草地农业系统的研究Ⅳ饲用玉米新品种生产性能比较

采用小区试验方式,在施肥水平、管理一致、同一播种密度的条件下,进行了不同饲用玉米Zea mays品种产量性能的比较研究.结果表明:在各个点不同饲用玉米品种产量差异达极显著水平(P＜0.01),3个点都是奥玉5102产量最高,其全株干物质平均产量达21 419.61 kg/hm2,且该品种品质好,植株健壮,叶片浓绿,保绿性好,株型半紧凑,是一个良好的饲用玉米品种.     

不同品种类型玉米不同器官和全株生物产量比较

本试验旨在比较不同品种类型玉米(Zea mays)不同器官和全株的生物产量,以提高玉米定向培育的选择效率。选择32种具有代表性的玉米优良品种为试验材料,根据淀粉性质、籽实外形、成熟性质和用途4种分类方法,分别对完熟期玉米的籽实、玉米芯、苞叶、叶片、叶鞘、茎秆及全株的鲜物质、风干物质、干物质以及粗蛋白质和总能产量进行比较。每个品种选择5个地块,每个地块选取10株玉米。结果表明:玉米的籽实、玉米芯、苞叶、叶片、叶鞘、茎秆和全株的鲜物质、风干物质、干物质、粗蛋白质和总能产量不同品种类型间差异均显著(P0.05)。根据淀粉性质、籽实外形和成熟性质分类不足以区别不同品种类型玉米的不同器官和全株生物产量(P0.05)。按用途分类,不同品种类型玉米不同器官和全株生物产量(玉米籽实的风干物质、干物质和总能产量除外)均差异显著(P0.05),表现为饲用玉米红粒玉米普通玉米糯玉米。对广泛种植的普通玉米和饲用玉米进行比较,设定普通玉米产量为100.0%,则饲用玉米籽实、玉米芯、苞叶、叶片、叶鞘、茎秆和全株的鲜物质产量分别为121.9%、164.2%、175.5%、149.0%、151.7%、168.8%和149.9%;风干物质产量分别为107.9%、143.7%、155.1%、139.4%、126.1%、162.0%和129.1%;干物质产量分别为107.5%、143.4%、155.0%、139.5%、125.7%、162.0%和129.21%;粗蛋白质产量分别为119.0%、142.9%、181.5%、161.6%、122.0%、137.4%和131.7%;总能产量分别为107.7%、143.8%、155.0%、139.4%、126.1%、162.0%和129.1%。玉米籽实干物质、粗蛋白质和总能产量占玉米全株的比例,普通玉米分别为47.75%、57.87%和48.49%,饲用玉米分别为39.72%、52.36%和40.48%。由此得出,普通玉米全株饲喂是"粮改饲"的最基本的策略,而饲用玉米籽实和全株生物产量都高于普通玉米,种植饲用玉米可以增加30%左右的土地利用。     

不同覆膜方式对饲草产量的影响

为了研究饲用玉米全膜双垄沟播和平膜种植对玉米生长发育、干物质含量及玉米产量的影响,试验选取了安定区广泛种植饲用玉米品种金凯5号、承3359和陕单8806为试验材料,对不同方式种植的玉米在拔节期、大喇叭口期和灌浆期用直尺测定玉米株高、称取测定单株重。结果显示：全膜双垄沟播的玉米株高、干物质含量、单株重均高于平膜种植的玉米。     

不同收获期青贮玉米品种农艺性状和生物学产量的研究

[目的] 研究不同收获期对2种玉米农艺性状和生物学产量的影响,选择适宜在内蒙古乌兰察布市凉城县制作青贮饲料的玉米品种以及最佳收获期。[方法] 以全株青贮玉米吉东81和粮用玉米甘优702为试验材料,试验期为2019年9月5日至10月5日,设11个收获日期,分析不同收获日期2种玉米株高以及各部位鲜物质产量、干物质含量和干物质产量的变化。[结果] 2种玉米株高随着收获期的延长呈先增加后平稳趋势,9月17日吉东81和甘优702的株高最高,分别为3.51 m和2.94 m,试验期间吉东81的平均株高显著（P<0.05）高于甘优702。2种玉米茎叶、秆、果穗和整株鲜物质产量呈先上升后下降趋势,干物质含量呈递增趋势,干物质产量呈先上升后平稳趋势。2种玉米整株平均鲜物质产量差异不显著（P>0.05）,吉东81的整株平均干物质含量和干物质产量显著（P<0.05）低于甘优702。[结论] 全株青贮玉米品种吉东81最佳收获期为9月23—26日,粮用玉米品种甘优702最佳收获期为9月17—20日,且在相同种植条件下全株青贮玉米品种吉东81更适合在内蒙古乌兰察布市凉城县推广。     

日本饲用高粱夏播试验及营养价值分析

从日本引进饲用高粱（Sorghum bicolor）种子,在甘肃省榆中县进行了夏播试验,对其生物学特性及适应性进行观测,并对其生长120 d后的草产量及牧草营养成分进行分析。结果表明,日本饲用高粱具有抗旱、抗寒、生长茂盛的优点,能适应榆中县的气候、土质、水肥条件;农田生长120 d后,鲜草产量达184.50 t·hm-2,干物质产量达43.46 t·hm-2,高于本地普通高梁成熟期产量。其全株主要营养成分与本地成熟期收获的普通高粱接近,总能约为本地高粱的2倍;与在日本种植至成熟期收获的全株营养成分相比,粗蛋白含量高59.91%,无氮浸出物含量高15.91%,粗纤维含量低20.14%,粗脂肪含量低72.52%。总体分析,日本饲用高梁是一种适应性强、产量高、营养价值高的饲料作物,适合在榆中县种植。     

"饲用玉米-黑麦草"草地农业系统的研究——V.饲用玉米性能评价与系统优化

在"饲用玉米-黑麦草"草地农业系统研究中,5月初播种的不同种类饲用玉米产量有较大差异.兼用型玉米奥玉5102干物质产量最高,达21 138.1 kg/hm2,是青刈型玉米玉草1号的干物质产量的3.15倍.通过种植系统优化,科饲1号-华农1号-杰威多花黑麦草种植系统产量最高,年干物质产量达44 303 kg,hm2,但兼用型玉米-杰威多花黑麦草种植系统成本较低.     

“饲用玉米—黑麦草”草地农业系统的研究——Ⅴ.饲用玉米性能评价与系统优化

在"饲用玉米-黑麦草"草地农业系统研究中,5月初播种的不同种类饲用玉米产量有较大差异。兼用型玉米奥玉5102干物质产量最高,达21 138.1 kg/hm2,是青刈型玉米玉草1号的干物质产量的3.15倍。通过种植系统优化,科饲1号-华农1号-杰威多花黑麦草种植系统产量最高,年干物质产量达44 303 kg/hm2,但兼用型玉米-杰威多花黑麦草种植系统成本较低。     

不同干物质含量全株玉米青贮营养成分及有机酸比较

本试验比较了不同干物质含量全株玉米青贮的感官评定、营养成分及有机酸含量.结果表明,饲用青贮玉米在干物质含量为32%～35%时收获,其感官评定等级高,可消化总养分中粗蛋白含量高,粗纤维含量低,且在青贮过程中产生的乳酸多、丁酸少,因此是适宜的收获时期,且较高的干物质含量能够明显改善青贮饲料的质量和品质.     

不同收获期玉米青贮干物质在奶牛瘤胃内降解率的研究

本文采用随机实验设计，利用瘤胃尼龙袋技术，测定全株玉米青贮分剐在乳熟、腊熟期收获时其干物质(DM)在奶牛瘤胃的降解率。结果表明：各期DM在奶牛瘤胃降解率依次为40．22％、53．24％。测试结果证明，在黑龙江省东部地区，腊熟期收获的全株玉米青贮对奶牛的饲用价值较高。     

“鉰用玉米-黑麦草”草地农业系统的研究——V.鉰用玉米性能评价与系统优化

在“饲用玉米-黑麦草”草地农业系统研究中，5月初播种的不同种类饲用玉米产量有较大差异。兼用型玉米奥玉5102干物质产量最高，达21138．1kg/hm^2，是青刈型玉米玉草1号的干物质产量的3．15倍。通过种植系统优化，科饲1号-华农1号-杰威多花黑麦草种植系统产量最高，年干物质产量达44303kg/hm^2，但兼用型玉米-杰威多花黑麦草种植系统成本较低。     

Spring Precipitation as a Predictor for Peak Standing Crop of Mixed-Grass Prairie

Ranchers and range managers need a decision support tool that provides a reasonably accurate prediction of forage growth potential early in the season to help users make destocking decisions. Erroneous stocking rate decisions can have dire economic and environmental consequences, particularly when forage production is low. Predictions must be based on information that is easily obtained and relevant to the particular range. Our goal was to evaluate monthly precipitation in spring months as a potential predictor of forage production compared to annual and growing-season precipitation. We analyzed the relationships between grazed and ungrazed peak standing crop (PSC) and precipitation using nonlinear regression and a plateau model, Akaike’s information criterion for model selection, and data from three locations: Streeter, North Dakota; Miles City, Montana; and Cheyenne, Wyoming. The plateau model included a linear segment, representing precipitation limiting production, and a plateau, an estimate of average production when precipitation is no longer the limiting factor. Both the response and predictor variables were rescaled so variability in production from average production was related to variability in precipitation from the long-term average. We found that grazing did not affect the relationship between PSC and precipitation, nor were annual or growing-season precipitation good predictor variables. The best predictor variable was total precipitation in April and May for Montana, May and June for North Dakota, and April, May, and June for Wyoming, with r² ranging from 0.74 to 0.79 for precipitation less than long-term average. These results indicate that spring precipitation provides useful information for destocking decisions and can potentially be used to develop a decision support tool, and the results will guide our choice of possible predictor models for the tool.     

甘南亚高山草甸水分与能量耦合对生产力的影响

在甘南亚高山草甸牧草生长期,应用FAO Penman-Monteith公式、土壤水分平衡原理、地面能量平衡原理,计算具有明确生物学特性并影响牧草生长发育的水分与能量耦合特性参量,并将特性参量和牧草生产力在时间上做同步分析,结果表明:特性参量对牧草的生长发育影响显著,具有双重气候相关特性,可作为牧草生长发育的综合判断指标和模型变量因子,建立实时的牧草生长发育状况动态评价体系和生产力预测系统模型。在年际变化上,特性参量对牧草生长的振荡性影响减弱消失,趋势性影响明显,特性参量失去双重气候相关性。年气候环境资源利用率不等于各生长季气候环境资源利用率之和,说明年际最大产量的形成是双重气候相关性共同作用的结果。气候因子综合分析表明,降水量与年际最大产量之间具有显著相关性。     

Estimating Grass Yield on Blue Grama Range From Seasonal Rainfall and Soil Moisture Measurements

To estimate annual forage production from moisture conditions it is important to consider the timing and seasonality of precipitation events as well as the past history of storm events. In this study we examined this relationship using 16 yr of annual measurements of herbaceous standing crop recorded at two study sites located on the Corona Range and Livestock Research Center in central New Mexico. Our hypothesis was that end-of-season herbaceous standing crop estimations could be improved using measured soil moisture instead of seasonal accumulations of rainfall as traditionally used for yield prediction. Daily recorded and simulated soil moisture levels were used to estimate the number of days over the growing season when soil moisture by volume was at low (< 20%), intermediate (20% to 30%), or high (≥ 30%) levels. Defining regression equations to include either simulated or probe-recorded measures of soil moisture improved the adjusted R² of the regression models from 46% for the rainfall model to over 60% for various soil moisture models. Key variables for explaining annual variation in herbaceous production included seasonal moisture conditions, the amount of broom snakeweed (Gutierrezia sarothrae [Pursh] Britt. & Rusby) present on the area, and the degree days of temperature accumulated over the growing season. Diurnal daily temperatures near historical averages were most advantageous for forage production. Simulated soil moisture data improved predictive grass yield estimates to a level equivalent to using onsite moisture probes to categorize daily moisture conditions. Potential exists to better predict forage conditions based on forecast information that uses soil moisture data instead of the traditional input of seasonal rainfall totals.     

青海省海南地区近30年≥0 ℃积温变化趋势分析

积温是作物与品种特性的重要指标之一,对积温农业气象重要指标的研究,对于指导农牧业生产具有十分重要的现实意义。本研究通过利用青海省海南藏族自治州共和、兴海、贵南、同德和贵德5县气象站的地面观测资料,对该地区近30年来≥0 ℃年积温的变化,主要农作物、牧草生育期的变化及其生育期≥0 ℃的积温变化做了分析,得出该地区大部分农作物及牧草的生育期有所缩短,开始期有所提前。由于近10年该地区升温明显,热量条件充足,各地≥0 ℃年积温有所增加,农作物及牧草发育期的积温增多,为该地区农作物及牧草的生长发育提供了充足的热量条件,对于该地区适时调整农牧业结构提供了依据。     

麦类作物粮饲兼用研究进展

粮饲兼用是指将营养期作物用于青绿饲草生产(放牧或刈割),待作物再生形成籽粒后收获籽粒的一种生产措施。这一措施已在全球10多个国家和地区广泛应用,以麦类作物的粮饲兼用最为普遍,一定程度上缓解了全球普遍存在的饲草供应季节性不均衡与家畜需求相对稳定的矛盾,促进了畜牧业的持续稳定发展。粮饲兼用的效益优势在于可确保作物籽粒生产的稳定,同时获取额外家畜生产收益。然而,不合理的粮饲兼用会导致饲草及籽粒的产量及品质均会受到影响,有必要开展相关研究以规范化粮饲兼用的应用模式。本文分析了麦类作物粮饲兼用的分布及其效益优势,深入分析了作物类型、播种时间及密度、水热条件等对粮饲兼用生产的影响,归纳得到如下4条技术要点。1)麦类作物可在分蘖期用于适度的利用,保留原有茎尖分生组织可维持籽粒生产的相对稳定。2)应优先选育冬性较强,早期生长缓慢,粮饲兼用不易破坏其茎尖分生组织且花期较晚的高秆品种用于粮饲兼用。3)粮饲兼用作物时,播种时间应提前2~4周,且需适当增加播种密度及提高底肥水平以增加饲草生产;为补偿饲草转移造成的氮亏缺,需在利用后适当添加氮肥以维持其籽粒生产。4)为保证粮饲兼用的效益优势,麦类作物粮饲兼用更适宜于在较湿润的地区(年降水量350~500 mm)开展。本文可为我国深入开展麦类作物粮饲兼用研究提供理论基础,并将进一步指导粮饲兼用措施的应用及推广。     

Sagebrush Control: At What Canopy Cover Is It Economically Justified?

We determine the economic threshold level for big sagebrush control based on 18 yr of forage-response data from an experiment conducted in Carbon County, Wyoming. We analyze the impacts of climatic variables and treatment site characteristics, such as sagebrush abundance levels, precipitation, and understory composition, on forage response and threshold level. We find that sagebrush canopy cover levels, April precipitation, May soil moisture, and understory composition are statistically significant factors in explaining forage response to sagebrush treatment. Forage yield across treated and untreated plots for 10 canopy cover levels, ranging from 4% to 40%, are analyzed via panel data regression techniques. We further investigate the impact of variability in precipitation and understory characteristics on economic outcomes of sagebrush control by analyzing three scenarios. Scenario 1 uses actual forage response data that include all variability from precipitation and understory composition. Scenario 2 uses regression-predicted yields across plots assuming average precipitation and soil moisture conditions. Scenario 3 uses regression-predicted yields assuming average precipitation, soil moisture, and understory characteristics across plots. Net present values based on value of grazing (for estimated yield differences between treated and untreated plots assuming 50% forage utilization) compared to treatment cost across sagebrush cover levels are estimated across these three scenarios. Results indicate that the economic threshold level of sagebrush infestation for the study period was between 8% and 24% for the analyzed scenarios. This indicates variability in precipitation and understory composition impact forage response and the resulting economics of sagebrush control. We conclude that range managers should consider potential control site characteristics and long-range weather forecasts when contemplating sagebrush control.     

气温和降水与天然草地牧草产草量的关联度分析

利用海晏县气象站1980-2006年降水、气温、大风日数以及青海省海晏县1980-2006年天然草地平均产草量,采用气候统计学方法和灰色关联法,进行了关联程度分析。结果表明：自80年代以来气候变暖变干,气候因子对牧草产量的影响非常明显,尤其是夏季降水和春季气温关联度最高。     

发展营养体农业的理论基础和实践意义

发展营养体农业可以发挥植物生长的各方面优势，充分利用植物的逻辑斯蒂生长规律，对光照强度的要求不高，对气候和土地资源的时间匹配性要求不严，通史减少漏光现象，提高光能利用率，容易避开主要病虫的危害，其生物量和经济产量较高，营养价值好，生产潜力大。在光照不足或热量不足的地区，发展营养体农业生产是对传统籽实农业系统缺陷的矫正，它可扬长避短，更充分地利用气候资源、土地资源和生物资源，使生物量和营养物质产量大幅度提高。在我国农业可持续发展中，对促进草业发展，解决因人畜共粮而导致的饲料粮短缺问题，促进农业结构调整，促进生态环境建设，促进现代化农业等,都将发挥重要作用。