Regression analysis can be used to investigate the association between a dependent variable (e.g., migration) and one or more independent variables (e.g., soil fertility, land degradation, aridity, etc).
Initially, the following potential predictor variables were individually assessed in a univariable binomial logistic regression model: flock-size, farm area, stocking density, whether the production system was sheep only or cattle and sheep, altitude, mean annual rainfall, mean annual temperature, soil texture, soil drainage, soil fertility, land cover, region and county.
Another application of this strain would be as an inoculum for a number of crop legumes that will significantly improve nodulation and nitrogen fixation and may lead to increase in plant dry matter under a low-level N fertilizer in low-fertility land.
Pongamia can grow on low-fertility land due to its nodulation properties and good N2-fixing symbiotic associations with "rhizobia" (a polyphyletic assemblage of alphaproteobacteria family: Rhizobiaceae), thus minimizing competition with food crops or related fertilizer, water, and land resources needed for food and fodder production [ 6].
Chongqing is a hilly-mountainous region characterized by ecological problems such as decreasing land fertility, soil erosion, and deforestation.
Various environmental conditions determine soil enzyme activities, which are important indicators for changes of soil microbial activity, soil fertility, and land quality.
In this model, the economy is thought of as a system, where the soil fertility of land that had been cleared is restored through the use of bio-sourced nutrients that otherwise might have to be treated or disposed of as waste (such as sewage, animal waste, food waste), thereby lowering the costs of imported fertiliser and raising the potential for new domestic industries.
Use of biochar from bio-wastes has been proposed as an option for improving soil fertility, degraded land restoration, and mitigating the greenhouse gas emissions associated with agriculture.
In addition, there is well-documented potential for environmental benefits from incorporating perennial grasses into agricultural landscapes with respect to soil fertility and land reclamation, water quality, and wildlife habitat [ 34, 35, 56- 58].
Accurate delineation of biomass distributions, at scales that range from local and regional up to global, becomes significant in reducing the uncertainty of carbon emission and sequestration, understanding their roles in influencing soil fertility and land degradation or restoration, and understanding the roles in environmental processes and sustainability [58].
For all farms in the study population the following data were extracted from their respective geographic data sources: mean annual rainfall (mm) for 2002 to 2005, mean annual temperature (°C) for 2002 to 2005, soil drainage, soil texture (i.e. clay, sand, loam or peat), soil fertility, and land cover characteristics.
