نتایج جستجو برای: crop
تعداد نتایج: 68120 فیلتر نتایج به سال:
Cash crop expansion has been a major land use change in tropical and subtropical regions worldwide. Quantifying the determinants of cash crop expansion should provide deeper spatial insights into the dynamics and ecological consequences of cash crop expansion. This paper investigated the process of cash crop expansion in Hangzhou region (China) from 1985 to 2009 using remotely sensed data. The ...
There is an urgent need for novel agronomic improvements capable of boosting crop yields while alleviating environmental impacts. One such approach is the use of optimized crop rotations. However, a set of measurements that can serve as guiding principles for the design of crop rotations is lacking. Crop rotations take advantage of niche complementarity, enabling the optimization of nutrient us...
A number of plant features and traits, such as overall plant architecture, leaf structure and morphological features, vascular architecture and flowering time are important determinants of photosynthetic efficiency and hence the overall performance of crop plants. The optimization of such developmental traits thus has great potential to increase biomass and crop yield. Here, we provide a compre...
Root and soil samples from one-crop and two-crop rice fields were collected in a survey for Hirschmanniella spp. in Vietnam during 1978-80. Hirschmanniella spp. were found in 50-78% of the soil samples and 98-100% of the root samples collected. Population densities of nematodes in root systems were lowest at posttransplanting and highest at heading time. Numbers of nematodes inside roots increa...
The crop immune response against Salmonella Enteritidis (SE) challenge in eight commercial egg-layer strains (five white-egg layer and three brown-egg layer) and specific-pathogen-free (SPF) White Leghorn (WL) hens was investigated. Pre- and post-SE challenge mucosal immune responses within the crops were evaluated. Commercial layers and SPF WL hens were orally challenged with 10(8) CFU/ml SE P...
Agricultural producers face many risks in their economic activity due to weather conditions, plant or animal diseases, price volatility, policy changes and so on. One of the management tools to deal with some of these risks is the crop insurance system. In Catalonia (North-East of Spain) farmers’ participation in crop insurance for vegetables is low. Only 5 percent of the vegetables area is ins...
Crop growth and productivity are determined by a large number of weather, soil and management variables, which vary significantly across space. Remote Sensing (RS) data, acquired repetitively over agricultural land help in identification and mapping of crops and also in assessing crop vigour. As RS data and techniques have improved, the initial efforts that directly related RS-derived vegetatio...
Information on rice crop phenology is important for crop management. This study aimed to detect rice crop phenology in the Vietnamese Mekong Delta using time-series MODIS data in 2007. Data processing steps included: (1) constructing time-series MODIS NDVI data, (2) filtering noise from the time-series data using empirical mode decomposition (EMD) and wavelet transform, (3) detecting rice crop ...
This study aimed at analysing patterns of crop sequences over time throughout the German federal state of Lower Saxony from 2005 to 2012. Therefore, the IACS (Integrated Administration and Control System) data was analysed for the identification of spatial and temporal pattern of crops grown on farmer’s fields. Lower Saxony is a region where maize growing had a steep increase and, therefore, wa...
A study of equilibrium acreage allocation decisions at the farm and regional levels under risk aversion, yield uncertainty, and endogenous crop prices is undertaken in a two-crop, two-region setting. The main insight is that a partial specialization in one crop at a regional level may be an equilibrium dominant strategy relative to the more diversified crop mix produced on farm. This is due to ...
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