نتایج جستجو برای: soil fertility
تعداد نتایج: 224095 فیلتر نتایج به سال:
Several reasons contributed to the low success of early trials, including varieties that were not adapted to the soils, climatic conditions and photoperiod of the region. Most of the trials were carried out in the Delta, where the night temperatures were too low for the varieties used. In additions, the Delta soils were very fertile, while the varieties tested were bred to produce an adequate y...
Despite limitations of low fertility and high acidity of the soils, the cerrado flora is the richest amongst savannas. Many cerrado woody species show sclerophyllous leaves, which might be related to the availability of water and nutrients in the soil. To better understand the function and structure of cerrado vegetation within its own variations, we compared two cerrado communities: one in its...
Mechanical hill direct seeding of hybrid rice could be the way to solve the problems of high seeding rates and uneven plant establishment now faced in direct seeded rice; however, it is not clear what the optimum hill seeding density should be for high-yielding hybrid rice in the single-season rice production system. Experiments were conducted in 2010 and 2011 to determine the effects of hill s...
This article analyzes geo-referenced data to elucidate the relations between deforestation and access to roads and markets, attributes of the physical environment, land tenure, and zoning policies in Santa Cruz, Bolivia. It presents separate models for Santa Cruz as a whole and for seven different zones within Santa Cruz, as well as for two different time periods (pre-1989 and 1989 to 1994). Th...
There is lack of adequate information on the fertility situations of the soils of Abakaliki urban flood plains. Farming activities have therefore been carried out on the surrounding uplands only. This study was therefore conducted in 2009 raining seasons, to evaluate the fertility status of the flood plains and compare it with the fertility of the uplands with a view to making recommendations f...
The selection of genotypes under high soil fertility may alter the effectiveness of mycorrhizal symbioses naturally forming between crop plants and the mycorrhizal fungi residing in cultivated fields. We tested the hypothesis that the mycorrhizal symbiosis of 5 landraces functions better than the mycorrhizal symbiosis of 27 cultivars of durum wheat that were bred after the development of the fe...
درک الگوی توزیع مکانی ماکروفون خاک بدلیل اثرات آن روی فرآیندهای اکوسیستم بسیار مهم است. لیکن اطلاعات کمی در این خصوص وجود دارد. درمورد تنوع زیستی ارگانیسم ها وجانداران خاکزی که ازاجزای مهم وکلیدی درهرسیستم اکولوژیکی هستند و در بهبود حاصلخیزی خاک و تولیدات زمین وپایداری اکوسیستم ها(ازطریق فرآیندهای بیولوژیک)نقش عمده دارند تحقیقات کمی انجام شده است. این تحقیق جهت بررسی الگوی مکانی پارامترهای تنوع...
Soil and foliage samples were collected from 136 sample sites in forested areas of the Dhulikhel Watershed, Nepal. Analyses showed that the soils have small values for pH, base saturation, total nitrogen, carbon and available phosphorus. Sample sites were stratified on the basis of aspect and elevation, soil type, forest type and management and the strata were compared to determine the influenc...
1. Desertification negatively impacts a large proportion of the global human population and > 30% of the terrestrial land surface. Better methods are needed to detect areas that are at risk of desertification and to ameliorate desertified areas. Biological soil crusts are an important soil lichen-moss-microbial community that can be used toward these goals, as (i) bioindicators of desertificati...
Cyanobacteria play an important role in increasing soil fertility as one of the biological soil crust in rangelands. They have a significant effect on improving soil fertility because of nitrogen and carbon fixation. In this study, the effect of different concentrations of cyanobacteria as one of the soil biomasses and finally to determine the best concentration for optimizing soil fertility in...
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