CPIDS: a plant parameter selection program for erosion prediction modeling     

James C Ascough II  Lois Ann Deer-Ascough  Glenn A Weesies 《Computers and Electronics in Agriculture》1998,20(3):263-276

Newly developed erosion prediction models require detailed input parameters including those describing cropping systems. Each model exhibits a different level of complexity for crop growth modeling, and many plant parameters for these models are difficult to obtain. Furthermore, numerous parameters require interpretation from other measurable plant characteristics. We developed a database containing measurable plant characteristics to supply users of these new erosion prediction technologies with the necessary parameters. The new database supports the Revised Universal Soil Loss Equation (RUSLE) and the Water Erosion Prediction Project (WEPP) erosion prediction models. The Crop Parameter Intelligent Database System (CPIDS) was developed to assist crop database builders and users of RUSLE and WEPP in interpretation of plant characteristics and selection of plant parameters. CPIDS is a Microsoft® Windows™-based program, currently running on a personal computer (PC) under Windows 3.1™, Windows 95™ and Windows NT 4.0™.  相似文献   

Evaluation of Meat and Bone Meal as Replacement for Protein Concentrate in the Practical Diet for Sutchi Catfish,Pangasius hypophthalmus (Sauvage 1878), Reared under Pond Condition     

M. Abdul Kader  Mahbuba Bulbul  Saichiro Yokoyama  Manabu Ishikawa  Shunsuke Koshio  M. Sakhawat Hossain  Gias Uddin Ahmed  M. Arshad Hossain 《Journal of the World Aquaculture Society》2011,42(3):287-296

An 80‐d feeding trial was conducted to evaluate meat and bone meal (MBM) as replacement of protein concentrate (PC) in practical diets for sutchi catfish, Pangasius hypophthalmus. Triplicate groups of juvenile sutchi catfish (initial weight 4.80 g) were stocked at the rate of 20,000 fish/ha in 12 earthen ponds (30 m² each). Four isocaloric diets (4.12 kcal/g) were formulated by replacing 0 (Diet 1, control), 33 (Diet 2), 67 (Diet 3), and 100% (Diet 4) PC protein with MBM. The growth parameters [final weight, % weight gain, and specific growth rate (SGR)] of fish fed Diets 1, 2, and 3 were not significantly different (P > 0.05) from each other but were significantly (P < 0.05) higher than those in Diet 4. The protein content in fish fed Diet 4 was significantly (P < 0.05) lower than the others. The total production of fish in different treatments ranged between 1917 and 2648 kg/ha/80 d. A simple economic analysis determined that the highest net profit (Tk. 52,965/ha) was obtained with Diet 2 and the lowest (Tk. 27,127/ha) with Diet 4 having 100% PC protein replacement. From the results of the study it is concluded that MBM can substitute up to 67% PC protein in catfish diet without hampering the growth and feed utilization.  相似文献   

Simulating landscape catena effects in no-till dryland agroecosystems using GPFARM     

J.C. Ascough II  A.A. Andales  G.S. McMaster  K.C. DeJonge  L.R. Ahuja  D.L. Hoag 《Agricultural Systems》2010,103(8):569-584

This study evaluated the site-specific applicability and efficacy of the GPFARM decision support system (DSS) based on underlying simulation model performance for dry mass grain yield, crop residue, total soil profile water content, and total soil profile residual NO₃-N across a landscape catena for dryland no-till experimental locations in eastern Colorado. Relative error of simulated mean, normalized objective function (root mean square error divided by the observed mean), and index of agreement evaluation statistics were calculated to compare modeled results to observed data. A one-way, fixed-effect ANOVA was also performed to determine differences among experimental locations and summit, sideslope, and toeslope landscape positions. GPFARM simulations matched observed data trends, with the model correctly distinguishing variations between the summit and toeslope landscape positions. In addition, experimental observations and GPFARM simulations both indicated that the toeslope landscape position was the most productive for grain yield and also exhibited higher amounts of crop residue, total soil profile water content, and total soil residual NO₃-N. The GPFARM crop model performed adequately but was inconsistent in simulating winter wheat, corn, and sorghum dry mass grain yield. GPFARM performance in simulating crop residue was poorer than for crop grain yield. GPFARM predicted mean total soil profile water content was generally within ±20% of the observed mean across locations and landscape positions, with the model somewhat biased towards overpredicting total soil profile water content at the summit and sideslope landscape positions. Total soil profile residual NO₃-N was underpredicted by GPFARM across all locations and landscape positions by an average of 30%. Although GPFARM appears to have reasonably simulated long-term output responses across a landscape catena for the eastern Colorado experimental locations (especially given the simplifying assumptions in many of the GPFARM simulation components and the inherent variability present at the experimental plot level), different interpretations of GPFARM performance can be made depending on the evaluation statistic of interest. Furthermore, the model cannot fully account for water and chemical movement across the landscape catena; simulation results suggest that addition of a spatially-distributed routing component should offer improvements in GPFARM prediction accuracy across a catena where surface runoff or lateral subsurface flow is occurring.  相似文献   

The Effect of Exposure to Ascending/Descending Imbibition Temperatures in Saline Solutions on Shoot and Root Growth Allocation in Germinating Sorghum Seed     

M. A. Kader  S. C. Jutzi 《Journal of Agronomy and Crop Science》2003,189(6):418-421

Sorghum (Sorghum bicolor L. Moench) seeds were examined to determine the influence of exposure to ascending and descending imbibition temperature regimes on plumule and radicle axes behaviour of seed after treatment. Treatments included soaking in distilled water, 4.5 % NaCl or 4.5 % KCl for 3 days at three ascending or descending temperatures ranging from 11 to 21 °C. Root growth was enhanced by descending temperatures (21, 16 and 11 °C) over the 3‐day period, whereas ascending temperatures (11, 16 and 21 °C) increased growth differences between shoots and roots. Shoot–root growth was affected by imbibition temperature to a greater extent than germination. However, seed soaking treatments in NaCl or KCl did not improve root or shoot growth, but did improve germination rates.  相似文献   

Use of Ultrasound In Horses for Diagnosis of Left Dorsal Displacement of the Large Colon and Monitoring its Nonsurgical Correction     

ELIZABETH M. SANTSCHI dvm  Diplomate ACVS    DONNIE E. SLONE JR  dvm  MS Dipiomate ACVS WILBUR M. FRANK II  dvm 《Veterinary surgery : VS》1993,22(4):281-284

During a 28 month period, 82 horses with clinical signs of abdominal pain were examined for left dorsal displacement of the large colon (LDDLC) using percutaneous ultrasound. Left dorsal displacement of the large colon was diagnosed when a gas echo dorsal to the spleen obliterated the dorsal splenic border, or when the colon was observed lateral to the spleen. In 42 horses, ultrasound confirmed a diagnosis of LDDLC and 40 horses had no evidence of LDDLC. There were five false negative results and no false positives. In four horses with LDDLC, the colon was displaced between the spleen and body wall; three of these colic episodes resolved with medical therapy and the fourth required a celiotomy to relieve a sand impaction. The remaining 38 horses had a renosplenic entrapment; surgical correction was elected in 4 horses, 21 horses were corrected by a nonsurgical rolling procedure, 12 were corrected at surgery after an unsuccessful rolling attempt, and one was corrected by rolling but required surgery later because of an additional lesion. Percutaneous abdominal ultrasound was a valuable aid in the diagnosis of LDDLC and in confirming correction of the displacement after a nonsurgical rolling procedure.  相似文献   

Clinical, Clinicopathologic, and Epidemiologic Features of Anhidrosis in Central Florida Thoroughbred Horses     

I. G. Mayhew BVSc  PhD  H. O. Ferguson II DVM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1987,1(3):136-141

A group of 834 Thoroughbred horses was surveyed on four central Florida farms for clinical and epidemiologic features of anhidrosis. In addition, comparative analysis was made of serum thyroxine, serum electrolytes, and fractional urinary electrolyte excretion ratios. An overall disease prevalence of 6.12% was observed. Training horses and nonpregnant broodmares had a predilection for the disease. Adolescent horses were infrequently affected. There was no correlation with sex or color. Comparative clinical signs, related to thermoregulatory compromise, included tachypnea and hyperthermia. Long-term effect included focal and generalized alopecia, decreased appetite, and impaired performance. Previously reported hypothyroidism and hypochloremia were not demonstrated; however, fractional urinary chloride excretion ratios indicated a significant relative conservation of chloride.  相似文献   

天山野苹果林立地条件和林分结构对苹果小吉丁种群数量的影响     

马志龙  彭彬  卡德艳·卡德尔  张元明  阿地力·沙塔尔 《新疆农业科学》2020,57(7):1338-1348

【目的】 研究苹果小吉丁Agrilus mali Matsumura自然种群在天山野苹果林的发生及其与影响因子之间的关系。【方法】 基于17块天山野苹果林标准地,以苹果小吉丁为研究对象,研究天山野苹果林生态系统中海拔、坡度、坡位、坡向等立地因子和林分郁闭度、林分密度、野苹果比例、树种丰富度等林分因子对苹果小吉丁种群影响效应等,构建预测模型。【结果】 海拔＞1 400 m的林分内平均虫口数量最低,仅为0.49头/m样枝,1 250～1 299 m平均虫口数量最高,达到1.26头/m样枝。随着样地坡度的增加,苹果小吉丁种群数量逐渐降低,缓坡(6°≤坡度≤15°)林分的平均虫口数量最高,达到1.24头/m样枝,显著高于陡坡(26°≤坡度≤35°)的0.39头/m样枝(P＜0.05)。林分郁闭度为0～0.29的林分虫口数量最高,达到1.44头/m样枝,显著高于郁闭度为0.30～0.49和0.50～0.79的林分(P＜0.05)。林分密度＜0.11的稀疏林分平均虫口数量最高,为1.5头/m样枝。海拔和坡度偏相关系数绝对值较大,分别为0.598和0.542,是苹果小吉丁虫口数量的关键影响因子,两者与平均虫口数量的关系达到显著水平(PX₁=0.031;PX₃=0.047;均小于0.05)。由海拔(X₁)、坡度(X₄)与苹果小吉丁虫口数量(Y)建立的多元回归模型为:Y=5.541-0.003X₁-0.033X₄。经F检验该线性回归预测模型达到显著水平(F=12.021,df=2,16,P=0.001)。将预测值与实测值进行比较,平均差异度为0.193;对实测值与预测值进行独立样本T检验,两者之间无显著差异。【结论】 海拔和坡度是影响苹果小吉丁种群数量的关键因子,其次为坡位,而林分郁闭度、林分密度、坡向、野苹果比例和树种丰富度对苹果小吉丁种群数量的影响作用稍弱,均为非主要因子。  相似文献   

Evidence for a role of dietary fiber type on hydration status of horses performing endurance exercise     

H.S. Spooner  B.D. Nielsen  H.C. Schott II  C.I. O'Connor-Robison  P.A. Harris 《Journal of Equine Veterinary Science》2009

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Zeitstudien in der Holzhauerei ausgeführt von der badischen Staatsforstverwaltung in den Jahren 1931 und 1932     

Referenten der Forstabteilung  Oberforstrat Karl Müller II 《European Journal of Forest Research》1932,54(22):767-776

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Enumeration of Bradyrhizobium japonicum in soil subjected to high temperature: Comparison of plate count, most probable number and fluorescent antibody techniques     

A. C. Kennedy  A. G. Wollum  II 《Soil biology & biochemistry》1988,20(6):933-937

The survival of BradyrMzobium japonicum strains in autoclaved and non-autoclaved soil at various temperatures for up to 18 days was determined by plate count, plant infectivity-most probable number (MPN) and modified fluorescent antibody (FA) techniques. The high-temperature tolerant strains studied were BR587, NC1005 and NC1033, and the high-temperature intolerant strains studied were NCI028, 3Ilb24 and 311b123. Each strain was exposed individually in a sandy loam soil at 28, 33 or 37°C under humidity controlled conditions. Those strains reported to be tolerant to elevated temperature in pure culture decreased by <10^1.5 cells g⁻¹ when enumerated by plate count after high-temperature exposure in autoclaved soil. Based on plate counts, the population of two of the three high-temperature intolerant strains added to autoclaved soil decreased by more than 10³ cells g⁻¹ soil after exposure to elevated temperatures. In non-autoclaved soil, the population of all inoculated strains decreased after exposure to elevated temperature when enumeration was by the plant infectivity-MPN technique. In autoclaved soil at 28°C, the correlation between plate count and FA enumerations was significant at the 0.05 probability level for four of the six strains (r² = 0.65). After high-temperature incubation, counts based on the FA technique were not correlated with plate counts of intolerant strains or MPN enumeration of tolerant and intolerant strains (r² = 0.004). Differential survival of B. japonicum strains in autoclaved soil at high temperature as enumerated by plate counts confirms the designation of temperature tolerance made by Munevar and Wollum (1981). However. MPN enumeration of bradyrhizobia in the non-autoclaved system did not follow the original temperature tolerance classifications. Enumeration by FA procedures did not show a decrease in population after exposure to high temperature as observed with the plate and MPN counts. Thus, the FA technique may not adequately indicate population dynamics in short-term ecological studies.  相似文献