The effect of land use change on soil fertility parameters in densely populated areas of Kenya

Abstract

The current study seeks to assess sustainability of agricultural land use by identifying the effect of land use change on soil quality using cross-sectional data collected through a household survey among 525 farm households in densely populated areas of Kenya. Soil samples were collected, analyzed and compared across three land use types: undisturbed, semi-disturbed and cultivated. To achieve these objectives, descriptive, Nutrient Index approach and Classification and Regression Tree (CART) analysis methods were used. Results indicate that within a period of five decades, agricultural land use has led to a decline in Total Organic Carbon (−72%), Magnesium (−65%) and Boron (−61%), Iron (−22%) and Total Nitrogen (−15%). The drivers of deterioration identified were cutting across inherent properties such as soil chemical (pH), physical (soil mapping unit) and biological (organic carbon) attributes, farmer practices (agricultural commercialization) and exogenous factors (population density and Agro-ecological zones). The study concludes that indeed conversion of land from natural vegetation is associated with deterioration in soil quality and therefore policy needs to create incentives for the build-up of soil organic matter, replenishment of soil macro and micro nutrients. Blending of commercial fertilizers with targeted micro-nutrients, maintenance of soil conservation techniques and long term fallowing are encouraged.

Soil Biological Fertility and Bacterial Community Response to Land Use Intensity: A Case Study in the Mediterranean Area

“…Our results showed that the highest value of BFI was obtained from grass-covered vineyard. It has been previously reported that soil fertility is proportional to the soil microbial activity and SOM, as well as altering environmental conditions and land uses [47,48]. It has also been proved that crop residues and cover crops increase soil microbial biomass and activity and improve SOC sequestration in the long-term [49].…”

Research on the Relationship between Price Mechanism and Short-Term Behavior in Chinese Farmland Trusteeships

“…It is obvious, based on results from studies by Chinese and foreign academics, that foreign academics place more of their focus on the effects that tillage [27], cultivation [28], stakeholders' knowledge [29], biofuels [30], and sustainable development ideas [31] have on sustainable land utilization behaviors than on problems with China's present land policy. While Chinese academics have noted that economic factors such as unsound contracts, high risk of breach of contract, and the instability of management rights are primary reasons behind the use of short-term contracts and short-term behaviors in land trusteeship in China, no effective contract system has yet been developed.…”

Evaluation of Spatial Variability of Some Soil Properties and Fertility Status Using Nutrient Index and GIS in Bilqas District, Dakahlia Governorate, Egypt

“…While, nutrient index for salt index (2.09) and exchangeable Ca (2.27) were medium; these data indicate to that the soil fertility status was medium according to EC and exchangeable Ca. Additionally, soil fertility status was high according to nutrient index of these parameters as following: soil reaction index (3.00), organic matter (2.45), available P (2.45), available K (2.913), CEC (2.45), C/N ratio (2.36), exchangeable K (2.64), exchangeable Na (2.45) and exchangeable Mg (2.91), (Verma et al, 2005;Abah and Petja, 2015;Willy et al, 2019 andEl-Seedy, 2019). Table 7.…”

“…A nutrient index (NI) of soil properties is distribution estimate percent of soil samples through three classes: high, medium and low of nutrient status (Willy et al, 2019). Nutrient index can be used as a guide and indication on soil fertility status (organic carbon, available phosphorus, available potassium and soil reaction index).…”