基于ZigBee技术的牧场火情监控系统设计研究

设计了一种将ZigBee技术引入到牧场火情监测系统中的方案,构建一个基于zigBee无线传感器网络的牧场火情实时监测系统。该系统可以实时监测牧场的相关参数,如空气湿度、温度及牧场的烟雾浓度变化情况等,为牧场防火灭火提供信息支持。研究了ZigBee无线传感器网络节点的电路设计、节点信息的采集、数据融合、传输以及传感器网络的有效拓扑结构。     

Growth of native forest species planted on abandoned pasture land in Costa Rica

Many forest plantations in the humid neo-tropics are established on degraded soils in abandoned pasture land and, with some exceptions, the species planted have not grown successfully. Studies of adaptability and growth under these conditions are scarce, particularly for native species. In this paper we present data on growth and tree form at 3 years of age for 11 species planted in abandoned pastures. The research plantation was established at La Selva Biological Station, in the Atlantic lowlands of Costa Rica (10° 26′N, 83° 59′W). Survival, diameter at breast height (DBH), total height, basal area, volume index and tree form were used to evaluate the species performance. After 3 years, Vochysia guatemalensis displayed a survival significantly higher (98%) than that of the other species. The lowest survival was 75% for Pinus tecunumanii. There were significant differences in growth measures among species. Acacia mangium exhibited significantly higher growth rates than the other species. Although this species grew rapidly, it did not develop straight single stems. About 14% of trees of A. mangium had bifurcation below DBH and more than 50% showed multiple axes or branches as large in diameter as the principal axis. The native species with the highest growth rate was Vochysia guatemalensis (DBH 12.7 cm, total height 7.5 m, volume index 55 m³ ha⁻¹ at 3 years of age). Vochysia ferruginea exhibited a slightly lower growth rate. Both Vochysia species were ranked highly with regard to tree form, with more than 80% straight single stemmed trees. The lowest growth rates were exhibited by Pentaclethra macroloba, Pithecellobium macradenium and Virola koschnyi; however, the latter two species formed straight single terms. Pentaclethra macroloba and Inga edulis failed to form straight single stems. In general, the growth rates of the species studied were high in comparison with results reported from other tree plantations in the tropics. In spite of this, it is not prudent to draw final conclusions on the basis of these 3 year measurements.     

青海省2005年草原虫害防治存在问题及建议

青海省农牧区由于春季干旱、夏季多雨等原因,导致害虫发生种类多、面积大、分布广;主要危害种类为草原毛虫、草原蝗虫、古毒蛾及草地螟。本文针对防治工作存在经费不足、规模小、器械落后、成本高、孵化期差异性大等问题,科学地提出了今后进一步加强虫防工作的建议。     

御道口牧场山地苗圃建设前景探析

该文叙述了河北省承德市御道口牧场自然气候和土壤植被分布状况等基本情况,并结合山地苗圃的发展背景及御道口牧场独特的区域优势,分析了御道口牧场建设山地苗圃对其生态文明所产生得巨大影响。     

多功能自走式牧草育种小区作业机械传动系匹配优化

针对集旋耕、播种、割草和运输功能于一体的多功能自走式牧草育种小区作业机械动力传动系统,在发动机台架试验基础上,利用Matlab开发的优化设计软件进行了优化匹配研究.通过对动力传动系统动力性和燃油经济性模拟仿真,并对动力与传动系统匹配计算,选取最佳的发动机与传动系统匹配方案.对优选出的发动机与传动系统最佳的匹配方案进一步优化设计,得出优化后的传动参数为:1挡传动比2.003 9、2挡传动比1.459 5、3挡传动比0.977 5、4挡传动比0.675 1、倒挡传动比1.984 0、高挡和低挡传动比分别为1.047 8和3.110 2、中央传动比为5.371 1.优化后多功能自走式牧草育种小区作业机械的动力性和燃油经济性都得到改善,优化后的传动系与动力的匹配度提高了6.29％.     

Pasture and forage crop systems for non-irrigated dairy farms in southern Australia. 2. Inter-annual variation in forage supply,and business risk

Inter-annual climatic variability poses a substantial management and profitability challenge for pasture-based dairy producers in southern Australia. The effects of a range of seasonal scenarios on the production and profit of non-irrigated dairy farm systems using several different forage bases were investigated for two regions in southeast Australia using a systems modeling approach. For the Terang district, seasonal scenarios were constructed around combinations of early, average or late autumn rains, and short, average or long spring flushes. For the higher-rainfall Ellinbank district, scenarios were constructed around either above- or below-average summer–autumns or winter–springs.     

Comparison of two pasture growth models of differing complexity

Two pasture growth models that shared many common features but differed in model complexity were refined for incorporation into the Integrated Farm System Model (IFSM), a whole-farm model that predicts effects of weather and management on hydrology, soil nutrient dynamics, forage and crop yields, milk or beef production, and farm economics. Major differences between models included the explicit representation of roots in the more complex model and their effects on carbon partitioning and growth. The simple model only simulated aboveground processes. The overall goal was to develop a model capable of representing forage growth and ecosystem carbon fluxes among multiple plant species in pastures while maintaining a relatively simple model structure that minimized the number of required user inputs. Models were compared to observed yield data for 12 site-years from three experiments in central Pennsylvania, USA. Both models underestimated observed yield by 6% when averaged across site-years. However, the simple model provided a better fit to the one-to-one line between observed and simulated yield than did the complex model. The models also showed similar relationships between yield and gross primary productivity (GPP), despite the fact that the complex model was specifically developed to optimize simulation of GPP. The simple model predicted much greater shoot respiration and carbon partitioning to above ground plant tissues, but less shoot senescence than the complex model. Published data on the proportion of GPP consumed in aboveground or total plant respiration exhibit a wide range of values, making it impossible to determine which model provided the best representation of respiration rates and, thus, of the entire carbon budget.     

新疆沙尔套山天然草地主要混合牧草营养指标近红外光谱分析

为了对新疆沙尔套山天然草地主要牧草营养指标进行快速、无损检测,本试验采用近红外光谱技术（Near infrared reflectance spectroscopy,NIRS）,进行修正偏最小二乘回归法（Modified partial least squares,MPLS）,结合散射处理、导数、平滑等不同的光谱预处理和数学处理方法,建立了32种主要牧草（草粉）的粗蛋白（Crude protein,CP）、中性洗涤纤维（Neutral detergent fiber,NDF）、酸性洗涤纤维（Acid detergent fiber,ADF）、粗灰分（Ash）、钙（Ca）和磷（P）的校正模型。结果表明：CP、NDF、ADF、Ash、Ca和P的交叉检验决定系数（R²）分别为0.82,0.80,0.78,0.50,0.72和0.65,交叉验证标准误差（Standard error of cross validation,SECV）分别为2.36,6.17,3.87,0.85,0.24和0.07,交叉验证相对分析误差（Relative percent deviation of cross validation,RPDCV）分别为2.78,2.26,2.39,1.92,2.39和1.65。最后结合外部验证集对各矫正模型进行验证。试验得出CP、NDF、ADF外部验证相对分析误差分别为2.67,2.20和2.28,相关性分别为0.66,0.73和0.84,其模型精确度和验证准确度还有待提高;利用近红外光谱检测技术不能建立Ash、Ca和P的检测模型。     

我国牧草及草坪草引种与生物入侵探讨

简述了生物入侵的概念、牧草及草坪草引种所带来的杂草入侵现状,并通过分析入侵性牧草及草坪草的形成过程、危害现状与引种利用的关系,阐明了在牧草及草坪草引种利用的同时,既要考虑经济效益,又要重视入侵物种引起的生态风险,并提出了我国牧草及草坪草引种造成生物入侵的预防对策。     

Effect of Sward Height on Pasture Nonstructural Carbohydrate Concentrations and Blood Glucose/Insulin Profiles in Grazing Horses

Six mature stock-type geldings with maintenance only requirements were used in a randomized cross-over design to determine the effect of sward height on pasture plant nonstructural carbohydrate (NSC) concentrations and blood glucose and insulin concentrations. Horses were randomly assigned to one of two tall fescue (Lolium arundinaceum Schreb cv Max-Q, Pennington Seed, Madison, GA) grazing cells (0.37 ha) having two different sward heights for a period of 7 days: (1) short (approximately 15 cm; n = 3) or tall (between 30 and 40 cm; n = 3). After the first 7-day period, treatment groups were reversed by moving horses to ungrazed cells having similar characteristics to those used in the first 7 days, so that all horses receive all treatments resulting in six observations per treatment. Both short and tall grazing cells were mowed to a height of approximately 15 cm 32 days before the experiment starts. The short grazing cells were removed to approximately 15 cm at 11 days before the start of the first 7-day period and again 1 day before the start of each 7-day period. All horses had access to pasture for 10 h/d beginning at 8 AM and ending at 6 PM. Although not at pasture, all horses were individually housed in 3.7 × 12.2 m partially covered pens containing automatic water troughs and a crushed stone surface. Herbage mass (kg DM/ha) was determined by use of a falling plate meter for each pasture to ensure that both groups of horses had adequate dry matter to provide grazing for at least 7 days. On day 7 of each period, jugular venous blood samples were collected from each horse before being turned out to pasture, and then at 2, 4, 6, and 8 hours after turn-out. Pasture samples were also collected from each grazing cell at the same time blood samples were taken. Serum and plasma from blood samples were harvested and analyzed for insulin and glucose concentrations, respectively. Pasture samples were analyzed for water soluble carbohydrate (WSC), ethanol soluble carbohydrate (ESC), and starch. The sum of WSC and starch were used as an estimate of NSC. Area under the curve (AUC) and peak concentration were calculated for both plasma glucose (PPG) and serum insulin (PSI) concentration and were analyzed using analysis of variance for randomized cross-over designs. Pasture WSC, ESC, starch, and NSC concentrations were analyzed using analysis of variance for randomized complete block design. A P value of < .05 was considered significant. Mean pasture plant NSC, WSC, and ESC concentrations were lower (P < .001) in short as compared with tall. Pasture plant starch concentration was not different between treatments. Mean pregrazing plasma glucose concentrations, PPG concentrations, and plasma glucose AUC were not affected by treatment. Mean pregrazing serum insulin concentrations were not affected by treatment. Mean PSI and insulin AUC were greater (P < .01) when horses grazed tall, as compared with short. In conclusion, decreasing the sward height by mowing pasture decreased NSC, WSC, and ESC concentrations and subsequently decreased the postprandial insulin response of horses grazing the pasture. These findings may be important in developing strategies aimed at preventing insulin resistance in grazing horses.