Integrated management of irrigation water and fertilizers for wheat crop using field experiments and simulation modeling

The reported study aimed at developing an integrated management strategy for irrigation water and fertilizers in case of wheat crop in a sub-tropical sub-humid region. Field experiments were conducted on wheat crop (cultivar Sonalika) during the years 2002–2003, 2003–2004 and 2004–2005. Each experiment included four fertilizer treatments and three irrigation treatments during the wheat growth period. During the experiment, the irrigation treatments considered were I₁ = 10% maximum allowable depletion (MAD) of available soil water (ASW); I₂ = 40% MAD of ASW; I₃ = 60% MAD of ASW. The fertilizer treatments considered in the experiments were F₁ = control treatment with N:P₂O₅:K₂O as 0:0:0 kg ha⁻¹, F₂ = fertilizer application of N:P₂O₅:K₂O as 80:40:40 kg ha⁻¹; F₃ = fertilizer application of N:P₂O₅:K₂O as 120:60:60 kg ha⁻¹ and F₄ = fertilizer application of N:P₂O₅:K₂O as 160:80:80 kg ha⁻¹. In this study CERES-wheat crop growth model of the DSSAT v4.0 was used to simulate the growth, development and yield of wheat crop using soil, daily weather and management inputs, to aid farmers and decision makers in developing strategies for effective management of inputs. The results of the investigation revealed that magnitudes of grain yield, straw yield and maximum LAI of wheat crop were higher in low volume high frequency irrigation (I₁) than the high volume low frequency irrigation (I₃). The grain yield, straw yield and maximum LAI increased with increase in fertilization rate for the wheat crop. The results also revealed that increase in level of fertilization increased water use efficiency (WUE) considerably. However, WUE of the I₂ irrigation schedule was comparatively higher than the I₁ and I₃ irrigation schedules due to higher grain yield per unit use of water. Therefore, irrigation schedule with 40% maximum allowable depletion of available soil water (I₂) could safely be maintained during the non-critical stages to save water without sacrificing the crop yield. Increase in level of fertilization increases the WUE but it will cause environmental problem beyond certain limit. The calibrated CERES-wheat model could predict the grain yield, straw yield and maximum LAI of wheat crop with considerable accuracy and therefore can be recommended for decision-making in similar regions.     

收获期对青贮玉米产量的影响

黑龙江是中国最北、纬度最高的省份,随着畜牧业的发展,饲料不足已成为影响寒地畜牧业发展的瓶颈之一。围绕着人们对青贮玉米不同收获期的质量和缺乏理论依据和参考数据这一问题,以青贮玉米龙辐单208、东青1号、吉饲8号和中原单32为材料,研究了不同收割期对青贮玉米鲜草产量和干物质产量的影响,以期为北方寒地青贮玉米的优质、高产、高效生产及其合理利用提供理论与技术支撑。试验结果表明,青贮玉米整株鲜草产量在授粉后20～30天较高,干物质产量随着收获期的延迟而不断增加,不同青贮玉米品种的干物质分配差异很大。从干物质积累角度讲北方寒地青贮玉米适宜收获期为授粉后40～50天。     

不同采收期黄桃的品质特性和微观结构变化

为研究不同采收期对黄桃果实品质特性和微观结构的影响,以4种不同采收期的锦绣黄桃为试验原料,对果实感官品质、质地、色差、微观结构、营养品质进行分析。结果表明:不同采收期的黄桃品质特性和微观结构不同。I期(7月25日采摘)到III期(8月8日采摘),随采收时间的推迟,黄桃果肉可溶性固形物、水溶性果胶、可溶性蛋白、VC含量逐步积累上升,但可滴定酸、原果胶含量逐步下降。I期和Ⅱ期(8月1日采摘)采收的果实硬度较高,微观组织结构紧密,营养品质低于III期。IV期(8月15日采摘)采收果实已过熟,果实软化,组织结构疏松,口感甜软,营养品质低于III期。III期(8月8日采摘)采收果实营养、感官品质最佳,为黄桃鲜食的最佳采收期。本研究为湖南炎陵锦绣黄桃的鲜食适期采收提供了理论依据。     

扁穗雀麦种子成熟过程生理响应及适宜收获期研究

为探究扁穗雀麦种子成熟过程中的生理响应,明确适宜的收获条件和时间,以扁穗雀麦"江夏"和"黔南"为试验材料,对种子成熟过程中含水量、粒重、贮藏物质、酶活性和ATP进行研究.结果表明,随着种子的成熟,含水量呈持续下降趋势,但最大失水率在品种间有较大差异."江夏"在花后第33～38天失水率最高,每天为4.94％,而"黔南"在...     

Analysis of shift schedule for the automatic transmission vehicle based on fuzzy neural network

The advantages and disadvantages of present methods for shift schedule analysis of automatic transmission vehicle are analyzed. An optimum shift schedule method based on fuzzy neural network is proposed. The structure and algorithm with Takagi-Sugeno mode is studied. Fuzzy logic rules with two parameters and membership functions for shift schedule are established according to the skilled driver’s experience and expert’s knowledge. The membership functions and fuzzy logic rules are modified through train mechanism of artificial neural network based on experiment sample. The fuzzy neural network is trained and simulated. The simulation results indicate that this shift schedule method based on fuzzy neural network of Takagi-Sugeno model is feasible and correct.     

Some Agronomic Strategies for Organic Quinoa (Chenopodium quinoa Willd.)

Quinoa is a potential new seed crop for protein feed and human consumption in Europe, with tolerance to a range of abiotic stresses. For this purpose the study was planned to analyse the effect of important agronomic strategies like nitrogen level, N application strategy, row spacing and harvest time on yield and quality of quinoa. The experiments took place in the field of the experimental station of the Faculty of Science, University of Copenhagen. Three levels of organic nitrogen from slurry was used (60, 120 and 180 kg N ha^?1), supplied either all at once at sowing, or split between sowing and beginning of the reproductive phase. The effect of row spacing and harvest time was studied by harvesting seeds at seed maturity, which occurred 2–3 weeks prior to the mechanical harvest by threshing, and a couple of months after. Yield increased significantly (P ≤ 0.05) with an application up to 180 kg N ha^?1, reaching 2200 kg ha^?1. Increasing N also caused a significantly increased seed weight (up to 3.3 mg) and protein content (up to 17 %). N level did not affect number and amount of weeds. Split application with part of the N applied at bud formation did not have a significant effect on yield. Delayed harvest had a negative influence on seed weight, whereas protein content was stable after harvesting even a month after seed maturity. A late harvest significantly reduced seed germination, being reduced by 50 % after a 2‐month delay. A conclusion from this study is that both yield and protein content of seed can be manipulated by N level and application strategy. Harvest time is important for securing a high seed quality measured as seed germination, seed weight and protein content. A fast germination of quinoa is an important characteristic demonstrating that the crop has good possibilities for being well‐established in the field when free from weeds at the time of sowing. The choice of row spacing is important and depends on weed control method. Weed control strategy should be developed based on modern precision tools.     

不同采收期对阿克苏富士苹果贮藏品质的影响

以阿克苏红富士苹果为试材,研究了不同采收期对采后果实品质的影响,为苹果选择合理的采收期和保持果实良好的贮藏品质提供依据。结果表明:采收期对苹果呼吸高峰的出现时间影响较小,但对呼吸高峰的峰值影响明显;早期采收的果实硬度较大,但失重率也明显高于其他晚采果实;适宜采收期采收的果实在贮藏期间,其VC、可滴定酸、可溶性固形物含量变化幅度小。用于鲜食的果实可在10月22左右采收,此时果肉硬度为10.01 kg/cm2,固酸比为29.16,口感酸甜。用于长期贮藏的阿克苏红富士苹果的最佳采收期为11月1日左右,低温贮藏150 d后果实硬度≥8.79 kg/cm2,可溶性固形物含量≥14.67%。     

甜玉米不同采收期籽粒品质性状研究

为研究不同采收期甜玉米品质性状的变化,以7个国内生产主推甜玉米品种为研究材料,设置授粉后15、18、21、24、27、30天共计6个采收期,动态监测甜玉米籽粒含水率、果皮厚度和糖组分等指标。结果表明：（1）参试甜玉米品种的籽粒含水率在授粉后15~30天呈下降趋势,其籽粒含水率变幅为80.09%~68.76%。不同甜玉米品种间籽粒含水率的平均下降速率各异。‘京科甜608’、‘京科甜533’和‘中农大甜413’籽粒含水率下降速率相对缓慢。（2）参试甜玉米品种果皮厚度随授粉后天数增加呈先升高后降低的单峰变化趋势,峰值出现在授粉后21天左右。不同品种间籽粒平均果皮厚度以‘京科甜608’和‘米哥’最低,为78.40 μm;‘中农大甜413’最高,为91.63 μm。（3）参试甜玉米品种籽粒中葡萄糖和果糖含量在授粉后15~30天呈降低趋势,‘京科甜533’、‘京科甜183’、‘京科甜608’葡萄糖和果糖含量在授粉后15~24天相对较高。蔗糖和山梨醇含量随授粉后天数增加呈先升高后降低趋势,在授粉后21~30天,蔗糖含量以‘京科甜158’和‘米哥’含量相对较高。籽粒发育初期（授粉后21天之前）,籽粒中以果糖和葡萄糖为主,之后蔗糖逐渐增加。不同品种间,‘京科甜533’、‘京科甜183’、‘中农大甜413’和‘京科甜608’籽粒中总糖含量均高于‘米哥’,其籽粒中糖组分主要以果糖和葡萄糖等还原性糖为主,而蔗糖含量相对较低。     

双季晚稻测土配方施肥效果探讨

通过2012年在漳平市对双季晚稻采用配方施肥、习惯施肥和空白对照试验,结果得到水稻产量配方施肥区>习惯施肥区>空白区,实施测土配方施肥有利于提高水稻产量及经济效益。     

采收期对岳帅苹果采后贮藏品质的影响

以五个采收期的岳帅苹果为试材,研究不同采收期的果实在0℃条件下贮藏98 d期间品质的变化情况。结果表明,随着果实成熟度的增加,淀粉逐渐水解为糖,果实硬度、总酸与VC含量逐渐下降。采收期V(盛花期后159 d)的果实在采收时即接近完熟,品质下降较快,应在采后尽快上市销售;采收期Ⅲ、Ⅳ(盛花期后153～156 d)的果实贮藏后的品质优于其他采收期,适合较长期的贮藏。