نتایج جستجو برای: arable land is limited
تعداد نتایج: 7376123 فیلتر نتایج به سال:
Acid soils limit crop production on 30-40% of the world’s arable land and up to 70% of the world’s potentially arable land (Haug, 1983). Although the poor fertility of acid soils is due to a combination of mineral toxicities (aluminum and manganese) and deficiencies (phosphorus, calcium, magnesium, and molybdenum), Al toxicity is the single most important factor, being a major constraint for cr...
Soil is the vital foundation of terrestrial ecosystems storing water, nutrients, and almost three-quarters of the organic carbon stocks of the Earth's biomes. Soil organic carbon (SOC) stocks vary with land-cover and land-use change, with significant losses occurring through disturbance and cultivation. Although urbanisation is a growing contributor to land-use change globally, the effects of u...
copper extraction from heap 3 low grade ore at sarchechmeh is limited due to its mixed composition (copper oxide and sulphide minerals). changing this heap to a bioheap could improve the copper recovery.
The present period is characterized by a growing world population and a higher demand for more and better quality food, as well as other products for an improved standard of living. In the future, there will be increasingly strong competition for arable land and non-renewable resources such as fossil carbon-sources, water, and some minerals, as well as between food, feed, fuel, fiber, flowers, ...
China is a populous agricultural country, the arable land is the most basic resources which is needed for agricultural production, the quality of arable land has a direct impact on the entire agricultural production and development ,so to carry out the Evaluation of Farmland is a very important foundation work which is advantage to know china’s arable land resources and to improve the efficienc...
There is ample evidence that continuously existing forests and afforestations on previously agricultural land differ with regard to ecosystem functions and services such as carbon sequestration, nutrient cycling and biodiversity. However, no studies have so far been conducted on possible long-term (>100 years) impacts on tree growth caused by differences in the ecological continuity of forest s...
Marton (Argillic Perched-gley Pallic, Typic Endoaqualf), Ohakune (Typic Orthic Allophanic, Typic Hapludand), and Westmere (Mottled Mafic Melanic, Mollic Hapludalf) soils with differing structural vulnerability were compared at matched sites under different land uses. Topsoil samples (0-10 cm) from indigenous forest (>50 yr), permanent pasture (>50 yr), pine plantation (>20 yr), or arable croppi...
Land use change may influence many natural phenomena and ecological processes, including runoff, soil erosion, sedimentation and soil conditions. Decreasing of forest area in the North of Iran is one of the critical problems in recent years. The aims of this study are to detect land use changes between 1967 to 2002 using satellite images of Land Sat 7 ETM+ (2002), aerial photos and digital topo...
Traditional farming practices suggest that cultivation of a mixture of crop species in the same field through temporal and spatial management may be advantageous in boosting yields and preventing disease, but evidence from large-scale field testing is limited. Increasing crop diversity through intercropping addresses the problem of increasing land utilization and crop productivity. In collabora...
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