نتایج جستجو برای: crop production
تعداد نتایج: 652923 فیلتر نتایج به سال:
Efforts to anticipate how climate change will affect future food availability can benefit from understanding the impacts of changes to date. We found that in the cropping regions and growing seasons of most countries, with the important exception of the United States, temperature trends from 1980 to 2008 exceeded one standard deviation of historic year-to-year variability. Models that link yiel...
The potential movement of transgenes from genetically modified crops to non-genetically modified crops via insect-mediated pollen dispersal has been highlighted as one of the areas of greatest concern in regards to genetically modified crops. Pollen movement depends sensitively on spatial and temporal variation in the movement of insect pollinators between crop fields. This study tested the deg...
Food security and land required for food production largely depend on rate of yield gain of major cereal crops. Previous projections of food security are often more optimistic than what historical yield trends would support. Many econometric projections of future food production assume compound rates of yield gain, which are not consistent with historical yield trends. Here we provide a framewo...
This paper analyzes the effect of landowner risk preferences and land quality on the optimal mix of vertically integrated production and contracted production of an energy crop in a region characterized by heterogeneity in landowners’ risk preferences and land quality and with riskiness of returns from both energy crop and conventional crop production. We examine the determinants of the decisio...
This publication is written for those looking for a way out of the high risk, long hours, low pay, poor prices, and dim future associated with conventional cash crop production. There are viable alternatives to continuing in the cash crop business for those who can adjust their thinking. Finding alternatives to commodity crop production is the focus of this publication. Certain principles provi...
Introduction Conservation tillage systems using sweep plows or field cultivators leave a high percentage of crop residues on the soil surface, which protects the soil from wind and water erosion (Johnson, 1950; Jones and Johnson, 1982; Allen and Fenster, 1986; Johnson et al., 1974). These systems have been successful in semiarid areas because meager rainfall after plowing does not allow weeds t...
Large-scale use of the persistent and potent neonicotinoid and fipronil insecticides has raised concerns about risks to ecosystem functions provided by a wide range of species and environments affected by these insecticides. The concept of ecosystem services is widely used in decision making in the context of valuing the service potentials, benefits, and use values that well-functioning ecosyst...
2 The map on the title page shows the crop production value of China's cultivated land in Yuan per hectare (Reproduced from: Heilig, 1999). The map shows that there are great divergences in crop productivity between cultivated areas in China. Very " profitable " crop production is possible in the provinces of Hubei, Hunan and parts of Jiangsu. A very poor crop production value is generated in t...
To face future challenges in crop production dictated by global climate changes, breeders and plant researchers collaborate to develop productive crops that are able to withstand a wide range of biotic and abiotic stresses. However, crop selection is often focused on shoot performance alone, as observation of root properties is more complex and asks for artificial and extensive phenotyping plat...
If climate change affects pollinator-dependent crop production, this will have important implications for global food security because insect pollinators contribute to production for 75% of the leading global food crops. We investigate whether climate warming could result in indirect impacts upon crop pollination services via an overlooked mechanism, namely temperature-induced shifts in the diu...
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