全文获取类型
收费全文 | 168篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
林业 | 8篇 |
农学 | 13篇 |
基础科学 | 4篇 |
53篇 | |
综合类 | 11篇 |
农作物 | 20篇 |
水产渔业 | 4篇 |
畜牧兽医 | 37篇 |
园艺 | 7篇 |
植物保护 | 21篇 |
出版年
2023年 | 5篇 |
2022年 | 12篇 |
2021年 | 7篇 |
2020年 | 17篇 |
2019年 | 12篇 |
2018年 | 21篇 |
2017年 | 15篇 |
2016年 | 10篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 8篇 |
2011年 | 10篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 12篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2003年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1987年 | 2篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有178条查询结果,搜索用时 31 毫秒
51.
52.
Ullah Atta Akram Zahid Malik Saad Imran Khan Khalid Saif Ullah 《Genetic Resources and Crop Evolution》2021,68(7):2827-2847
Genetic Resources and Crop Evolution - Soybean is a high-nutritional crop that provides a sustainable source of dietary protein and edible oil for human consumption and animal diet. In this... 相似文献
53.
M. Akmal Khan Iftikhar A. Rana Ihsan Ullah 《Plant foods for human nutrition (Dordrecht, Netherlands)》1987,37(3):253-260
The nutritive value of some commercial wheat varieties grown in Pakistan was measured chemically, including amino acid analysis, and biologically in N-balance experiments with growing rats. The protein content ranged from 13.2% in Punjab-83 to 16% in Barani-83. Lysine per 100g protein varied between 2.46 and 2.75%. The available carbohydrate ranged from 67.3 to 74.7%. Iron content was highest in Sonalika while the concentration of zinc and manganese was highest in Sarhad-82. The protein digestibility (TD), biological value (BV) and net protein utilisation (NPU) varied between 92–95%, 56–68% and 53–65% respectively. Level of wheat protein was negatively correlated with available carbohydrate (r=–0.93), lysine per unit protein (r=–0.67) and BV (r=–0.76). The lysine content (g/16gN) of commercial wheat varieties showed a positive correlation (r=+0.95) with the BV. The protein quality was lowered in varieties having higher content of protein. 相似文献
54.
A sequential irrigation scheduling problem is the problem of preparing a schedule to sequentially service a set of water users. This problem has an analogy with the classical single machine earliness/tardiness scheduling problem in operations research. In previously published work, integer program and heuristics were used to solve sequential irrigation scheduling problems; however, such scheduling problems belong to a class of combinatorial optimization problems known to be computationally demanding (NP-hard). This is widely reported in operations research. Hence, integer program can only be used to solve relatively small problems usually in a research environment where considerable computational resources and time can be allocated to solve a single schedule. For practical applications, metaheuristics such as genetic algorithms (GA), simulated annealing, or tabu search methods need to be used. These need to be formulated carefully and tested thoroughly. The current research is to explore the potential of GA to solve the sequential irrigation scheduling problems. Four GA models are presented that model four different sequential irrigation scenarios. The GA models are tested extensively for a range of problem sizes, and the solution quality is compared against solutions from integer programs and heuristics. The GA is applied to the practical engineering problem of scheduling water scheduling to 94 water users. 相似文献
55.
Sajid Masood Tayyaba Naz M. Tariq Javed Ijaz Ahmed Habib Ullah Muhammad Iqbal 《Archives of Agronomy and Soil Science》2013,59(3):337-347
Farmyard manure (FYM) improves various soil parameters and to a large extent, the availability of water and nutrient to crops when it is applied to the soil. This study aims to further investigate the short-term effects of different levels of FYM on maize plants and soil parameters. Maize plants grown in pot culture were treated with no FYM (control), recommended NPK (inorganic fertilizers), and FYM at 2, 4, 6, 8, and 10 t ha?1 along with recommended NPK, and the cultures were analyzed 8 weeks after germination. Soil bulk density and soil pH decreased with the increasing levels of FYM, whereas soil porosity, soil organic matter (SOM), soil water content, plant height, root and shoot yield, and NPK uptake of maize were increased compared with the control or recommended NPK, respectively. The present results indicate that short-term application of higher FYM levels improves soil properties. Furthermore, the application of FYM at only higher rates significantly increases the nutrient uptake of maize plants due to improved soil properties. The supply of different amounts of nutrients increases biomass and nutrient uptake in plants. 相似文献
56.
Ur Rahman Shahid Basit Abdul Ara Neelam Ullah Izhar Rehman Attiq ur 《Gesunde Pflanzen》2021,73(4):541-553
Gesunde Pflanzen - Salinity is a complex abiotic stress that affects physiology and biochemistry of plants and significantly reduces both crop yield and quality. Considering the global... 相似文献
57.
Shoaib Akhtar Gu-cheng LI Adnan Nazir Amar Razzaq Raza Ullah Muhammad Faisal Muhammad Asad Ur Rehman Naseer Muhammad Haseeb Raza 《农业科学学报》2019,18(2):460-470
Farmers in Pakistan continue to produce maize under various types of risks and adopt several strategies to manage those risks. This study is the first attempt to investigate the factors affecting the concurrent adoption of off-farm income diversification and agricultural credit which the farmers use to manage the risk to maize production. We apply bivariate and multinomial probit approaches to the primary data collected from four districts of Punjab Province in Pakistan. The results show that strong correlations exist between the off-farm diversification and agricultural credit which indicates that the use of one risk management strategy leads to another. The findings demonstrate that education, livestock number, maize farming experience, perceptions of biological risks and risk-averse nature of the growers significantly encourage the adoption of diversification as a risk management tool while farm size inversely affects the adoption of diversification. Similarly, in the adoption equation of credit, maize farming experience, farm size, perceptions of price and biological risks and risk attitude of farmers significantly enhance the chances of adopting agricultural credit to manage farm risks. These findings are important for the relevant stakeholders who seek to offer carefully designed risk minimizing options to the maize farmers. 相似文献
58.
Alam Md. Ashraful Rahman Md. Mizanur Biswas Jatish Chandra Akhter Sohela Maniruzzaman M. Choudhury Apurba Kanti Jahan M. Abu Hena Sorwar Miah Md. Main Uddin Sen Ranjit Kamal M. Zia Uddin Mannan Md. Abdul Shiragi Humayun Kabir Kabir Wais Kalra Naveen 《Paddy and Water Environment》2019,17(4):677-688
Paddy and Water Environment - Rice-based cropping systems in Bangladesh have received little consideration of changing nitrogen (N) and carbon (C) in soil. Therefore, this study was conducted at... 相似文献
59.
Heavy metal-polluted water has become a problem for sustainable environment, agriculture, and human health. Phyto-accumulation is an eco-friendly technique for decontamination of metal-polluted water and soil. The efficiency of phyto-accumulation and rhizo-filtration can be enhanced by the application of certain nutrients to accumulator plants. In this study, we focused on the role of iron (Fe) in rhizo-filtration and phyto-accumulation of cadmium (Cd) from polluted water/media, using Ricinus communis plant. Medium was contaminated with 10 ppm Cd while Fe (2.50, 5.00, and 7.50 ppm) was applied both as foliar spray and medium addition separately. Accumulation of Cd and concentrations of soluble proline, phenolic compounds, and chlorophylls were measured in plant tissues. Addition of Fe into media significantly increased biomass in the plants but decreased Cd absorption by roots and its accumulation in other tissues of the plants. Foliar application of Fe, especially 7.5 ppm, significantly increased biomass as well as accumulation of Cd in tissues of the plants. Contents of soluble proline (41.88?±?3.56 ppm) and phenolics (171.00?±?4.98 ppm) in leaves were highly increased by foliar spray of 7.5 ppm Fe on the plants. On the other hand, highest concentrations of free proline (67.00?±?2.00 ppm) and total phenolics (82.67?±?2.52 ppm) in plant roots were observed in 7.5 ppm Fe added to media and as foliar spray, respectively. Strong correlations were observed between phenolics content in roots and leaves with Cd accumulation after foliar application of 7.5 ppm Fe. 相似文献
60.
Two experiments were conducted to evaluate the effects of dose and timing of silicon (Si) application on rice under limited water supply. The treatments for the first study included five Si doses (0, 75, 150, 300 and 600 kg Si ha–1) under three soil moisture conditions (100%, 75% and 50% field capacity). For the second study, the treatments were four Si application timings [100% basal, 50% basal + 50% panicle initiation (PI), 25% basal + 75% PI and 25% basal + 50% PI + 25% heading] at the dose of 300 kg ha–1 under the same moisture conditions. The highest number of panicle plant–1 (14.6) and grain yield (13.6 g plant–1) were obtained with the dose of 300 kg Si ha–1. Similarly, an increase of 34–45% in grain yield was observed for different Si application timings compared with the control. Shoot dry matter and grain yield had positive linear relationship with shoot Si content. Grain yield and number of spikelet panicle–1 were higher at the 300 kg Si ha–1 dose applied as 100% basal, and hence could be a feasible option for RD57 Thai rice variety under water-deficit conditions. 相似文献