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Crop planting structure optimization is a significant way to increase agricultural economic benefits and improve agricultural water management. The complexities of fluctuating stream conditions, varying economic profits, and uncertainties and errors in estimated modeling parameters, as well as the complexities among economic, social, natural resources and environmental aspects, have led to the necessity of developing optimization models for crop planting structure which consider uncertainty and multi-objectives elements. In this study, three single-objective programming models under uncertainty for crop planting structure optimization were developed, including an interval linear programming model, an inexact fuzzy chance-constrained programming (IFCCP) model and an inexact fuzzy linear programming (IFLP) model. Each of the three models takes grayness into account. Moreover, the IFCCP model considers fuzzy uncertainty of parameters/variables and stochastic characteristics of constraints, while the IFLP model takes into account the fuzzy uncertainty of both constraints and objective functions. To satisfy the sustainable development of crop planting structure planning, a fuzzy-optimization-theory-based fuzzy linear multi-objective programming model was developed, which is capable of reflecting both uncertainties and multi-objective. In addition, a multi-objective fractional programming model for crop structure optimization was also developed to quantitatively express the multi-objective in one optimization model with the numerator representing maximum economic benefits and the denominator representing minimum crop planting area allocation. These models better reflect actual situations, considering the uncertainties and multi-objectives of crop planting structure optimization systems. The five models developed were then applied to a real case study in Minqin County, north-west China. The advantages, the applicable conditions and the solution methods of each model are expounded. Detailed analysis of results of each model and their comparisons demonstrate the feasibility and applicability of the models developed, therefore decision makers can choose the appropriate model when making decisions. 相似文献
84.
Yuqin Wu Xiaonan Yin Youli Wang Tahir Mahmood Muhammad Shahid Dafei Yin Jianmin Yuan 《Animal Science Journal》2020,91(1)
This study was aimed to explore the comparative acidifying properties of 2‐hydroxy‐4‐(methylthio) butanoic acid (HMTBA) and a combination of DL‐methionine (DLM) and acidifier in male broiler production. A total of 480 1‐day‐old broiler chicks were randomly divided into four treatments: A (low HMTBA, 0.057% HMTBA); B (low acidifier, 0.05% DLM + 0.057% acidifier); C (high HMTBA, 0.284% HMTBA); and D (high acidifier, 0.25% DLM + 0.284% acidifier). At 21 d, growth performance, chyme pH, digestive enzyme activities, and intestinal microflora were measured. The pH of crop, gizzard, and ileum contents was higher in the HMTBA treatment group than in DLM + acidifier treatment group. Furthermore, acidifier supplementation promoted growth of butyrate‐producing bacteria such as Faecalibacterium, whereas high HMTBA (0.284%) inhibited the proliferation of acid‐producing bacteria including Roseburia and Collinsella. The chymotrypsin activity was lower in the HMTBA group than in the DLM + acidifier group. In contrast, high‐level HMTBA group showed higher average daily gain and average daily feed intake than the DLM + acidifier group. These results suggested that HMTBA work through different pathways with DLM plus acidifier. 相似文献
85.
为了给阿鲁科尔沁旗紫花苜蓿(Medicago sativa)灌溉提供科学依据,利用1984-2013年30年气象数据,采用联合国粮农组织推荐的彭曼-蒙特斯公式法,研究了阿鲁科尔沁旗紫花苜蓿需水规律和灌溉定额。结果表明,阿鲁科尔沁旗紫花苜蓿第1茬、第2茬、第3茬、第4茬、生长季、非生长季和全年需水量分别为221、187、169、179、755、70和825mm,需水强度分别为4.3、4.7、4.1、2.5、3.7、0.4和2.3 mm·d~(-1),灌溉需水量分别为194、118、66、131、508、56和564mm,灌溉定额分别为228、139、78、154、598、66和664 mm。 相似文献
86.
In Northern Europe, inter-row hoeing has become a popular tactic for controlling weeds in organic cereals. Hoeing is highly effective and can be implemented from crop emergence until stem elongation to maintain a nearly weed-free inter-row zone. However, hoeing has a lesser effect on weeds growing in the intra-row zone, where crop–weed proximity results in heightened competition. In the hoed cereal system, it is investigated whether tall-growing, competitive, cruciferous weeds in the intra-row zone affect crop biomass, yield and thousand kernel weight (TKW). An additive experimental design is employed to enable the fitting of rectangular hyperbolas, describing and quantifying the effects of increasing intra-row surrogate weed density on crop growth parameters. Regressions were studied under the influence of crop (spring barley and spring wheat), row spacing (narrow [12.5 or 15.0 cm] and wide [25.0 cm]) and nitrogen rate (50 and 100 kg NH4-N/ha). Cruciferous surrogate weeds were found to impact crop yield and quality severely. For example, ten intra-row plants/m2 of surrogate weed Sinapis alba reduced grains yields by 7%–14% in spring barley and by 7%–32% in spring wheat with yield losses becoming markedly greater in wheat compared to barley as weed density increases. Compared to wheat, barley limited yield and quality losses and suppressed intra-row weed growth more. Row spacing did not have a consistent effect on crop or weed parameters; in one of six experiments, the 25 cm row spacing reduced yields and increased intra-row weed biomass in wheat. Nitrogen rate did not affect crop or weed parameters. Results warrant the implementation of additional tactics to control intra-row weeds and limit crop losses. 相似文献
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88.
《湖南农业大学学报(自然科学版)》2015,41(5)
对江淮分水岭区域观测的8种农作物冠层光谱进行数据重采样和植被指数计算,分析了4种常用指数和6种常用传感器对农作物的识别能力,同时采用识别效率最高的数据变换形式构建了BP神经网络模型。结果表明:8种农作物的反射光谱曲线存在较大差异;6种传感器对农作物的识别能力由大到小依次为ETM+、QUICKBIRD、IKONOS、MODIS、ASTER、HRG;模拟得到的ETM+和QUICKBIRD的近红外与红光波段反射率计算的归一化植被指数(NDVI)和简单比值植被指数(SR)对农作物的识别能力较强;在不同的数据变换形式中,对农作物识别精度最高的是一阶微分(FD,波长间隔6 nm),识别精度达87.3%;以FD(波长间隔6 nm)为输入数据集构建BP神经网络模型,当隐含层节点数为15时,识别精度最高,达90.0%。 相似文献
89.
在以小麦淀粉、玉米淀粉、马铃薯淀粉和可溶性淀粉为碳源代替葡萄糖为碳源的 MRS培养基上检测了菌株 L actobacillus amylophilus JCM112 5活菌数的增殖状况以及葡萄糖和有机酸的代谢特征同时测定了 p H值的变化。结果表明以淀粉为碳源时菌株先分解淀粉成葡萄糖并累积到一定数量后再加以利用 ;活菌数呈现双曲线增长现象 ;丙酮酸、乳酸、乙酸和柠檬酸及另一未知有机酸的数量发生了较大的变化。 相似文献
90.
Foliar fertilizers (FF) applied at the reproductive growth stage was reported to increase soybean (Glycine max L. Merr.) yield in field trials. But yield increases have not been consistent. Field experiments were conducted on Calloway silt loam soil in 1981—1982 to determine the effect of two foliar fertilizer (FF) formulations, 16N + 4P + 4K + 1 S (Hanway) and 12 N + 4 P + 4 K + 0.5 S (Folian), and time of application, 0800- and 1900-h, on the growth of seven soybean cultivars from maturity groups V, VI, and VII. Foliar fertilizers were applied at a rate of 187 L/ha?1 in water by a backpack CO2 pressure sprayer at R5 to R6 growth stages. Foliar fertilizers caused no crop injury (leaf burn) when applied at 1900-h but caused moderate injury at 0800-h, which caused a yield reduction. The most significant crop injury was caused by Hanway formulation when applied at 0800-h. Yields were significantly reduced by FF in 1981 but not in 1982. Generally, Folian formulation treatments had higher yields than Hanway formulation treatments, but neither formulation increased yield above that of the untreated plants. The Bragg cultivar exhibited the least amount of crop injury and the most positive yield response to FF. Plant height, 100-seed weight and lodging rates were not adversely affected by the foliar applications. Due to the general lack of consistent yield increases or in some instances yield reduction from FF applications, the formulations used cannot be recommended for use by soybean producers. 相似文献