نتایج جستجو برای: soil fertility where the input labour
تعداد نتایج: 16142499 فیلتر نتایج به سال:
Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization are essential for sustainable agriculture. Quantifying the contribution of various fertilization regimes to soil N storage and loss has been lacking in a wide range of spatiotemporal scales. Based on data collected from field experiments at three typical agricultural zones in China, soil N dyna...
abstract global financial crisis has created too many problems in relations among governments. among these problems, the issue of global monetary management, more than every time in the past four decades, has been moved in the center of international economic attentions. a problem which is specially known with the monetary hostility between united states and public republic of china. where ar...
The differences in rhizosphere nitrification activities between high- and low- fertility soils appear to be related to differences in dissolved oxygen concentrations in the soil, implying a relationship to differences in the radial oxygen loss (ROL) of rice roots in these soils. A miniaturised Clark-type oxygen microelectrode system was used to determine rice root ROL and the rhizosphere oxygen...
Environmental philosophers spend considerable time drawing the divide between humans and the rest of nature. Some argue that humans and our actions are unnatural. Others allow that humans are natural, but maintain that humans are nevertheless distinct. The motivation for distinguishing humans from the rest of nature is the desire to determine what aspects of the environment should be preserved....
Rapid deforestation in Sumatra, Indonesia is presently occurring due to the expansion of palm oil and rubber production, fueled by an increasing global demand. Our study aimed to assess changes in soil-N cycling rates with conversion of forest to oil palm (Elaeis guineensis) and rubber (Hevea brasiliensis) plantations. In Jambi Province, Sumatra, Indonesia, we selected two soil landscapes - loa...
Fertilizations affect soil organic carbon (SOC) content but the relative influences of the edaphic and climate factors on SOC storage are rarely studied across wide spatiotemporal scales. This study synthesized long-term datasets of fertilization experiments in six typical Chinese croplands, and calculated annual C input from crops and manure amendments, changes in SOC storage (ΔSOC) and C sequ...
abstract: in this thesis, we focus to class of convex optimization problem whose objective function is given as a linear function and a convex function of a linear transformation of the decision variables and whose feasible region is a polytope. we show that there exists an optimal solution to this class of problems on a face of the constraint polytope of feasible region. based on this, we dev...
Soil fertility and nutrient-related plant functional traits are in general only moderately related, hindering the progress in trait-based prediction models of vegetation patterns. Although the relationships may have been obscured by suboptimal choices in how soil fertility is expressed, there has never been a systematic investigation into the suitability of fertility measures. This study, there...
Data mining involves the systematic analysis of large data sets , and data mining in agricultural soil datasets is exciting and modern research area. The productive capacity of a soil depends on soil fertility. Achieving and maintaining appropriate levels of soil fertility, is of utmost importance if agricultural land is to remain capable of nourishing crop production. In this research, Steps f...
Studying soil phosphorus fractions is useful in understanding soil pedogenesis as well as soil fertility. In this reseach, 20 soil samples were taken from different depths of 0-30 and 30-60 cm of upper-slope, mid-slope and lower-slope positions of four toposequences in arid (Jei and Ziar in Isfahan) and semiarid (Farokhshahr and Shahrekord) regions. In each toposequence, the soil depth was re...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید