Ann Verdoodt

Temperature and Precipitation Suitability Evaluation for the Winter Wheat and Summer Maize Cropping System in the Huang-Huai-Hai Plain of China

The Huang-Huai-Hai Plain is the most important winter wheat and maize production region in China. In response to the increasing population pressure, the Chinese authorities strongly invested in improving the irrigation systems and increasing ground and surface water exploitation within the plain to increase the crop productivity. This resulted in a reduction of water resource availability and in turn indirectly affected the suitability of various agricultural ecosystems in the plain. The main purpose of this study was to review the suitability of temperature and precipitation for the winter wheat and summer maize cropping system in the Huang-Huai-Hai Plain, in order to provide a preliminary irrigation scheme. This analysis provides a first attempt to enhance the water resource management as well as to increase the water use efficiency. For this aim, a GIS-based multicriteria analysis procedure has been developed consisting of (1) definition of objectives (evaluated entities) and database building; (2) definition of evaluation criteria; (3) standardization of the criteria; (4) combination of the criteria; (5) classification of the objectives; and (6) integration of the objectives. The land suitability classification maps were transformed into maps of required irrigation amounts for each growing stage of the winter wheat and summer maize cropping system. The study also exemplified the limitations and proposed future research activities that will improve the detail and accuracy of the evaluation results.

Impact Of Enclosure Management On Soil Properties And Microbial Biomass In A Restored Semi-arid Rangeland, Kenya

Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well.

Pedogenic impacts on the distribution of total and available Fe, Mn, Cu, Zn, Cd, Pb and Co contents of vertisols and vertic inceptisols of the Bale Mountain area of Ethiopia

5.9 to 41.5, 0.07 to 0.37, 0.70 to 1.73, 0.07 to 0.83, 0.04 to 1.31 and 0.0 to 0.02 ug/g, respectively. Available indices of the micronutrients studied are believed to be sufficient for plant growth except Zn, which is inadequate. Available heavy metal contents are below tolerable levels that can pose danger to man and livestock. Extractable micronutrients and heavy metals generally showed a decrease in concentration with depth associated with decreasing organic carbon contents and increasing pH and CaCO3 contents that exert a major influence on the availability of the micronutrients and heavy metals. Multiple linear and quadratic regression equations generally improved the predictive abilities for available Fe, Mn, Cu, Zn and Co over simple linear relationships when pH, EC, OC and CaCO3 were used as independent variables. Regression relationships developed constitute useful predictive indices for estimating micronutrients and heavy metals from existing soil survey reports of the Bale Mountain area.

Effects and Implications of Enclosures for Rehabilitating Degraded Semi-arid Rangelands: Critical Lessons from Lake Baringo Basin, Kenya

The establishment of enclosures, denoting areas closed off from grazing for a specific period, is a well-known management strategy for restoring degraded semi-arid rangeland ecosystems. Range enclosure has profound ecological (biophysical) effects and a number of socio-economic implications that vary significantly, depending on local conditions. Understanding the consequences of the rising trend of rangeland enclosure is thus imperative for sustainable planning and management of these fragile ecosystems. Indeed, what administrators require is not a general policy for or against enclosure, but rather some understanding of the various effects of enclosure under different circumstances. Ultimately, researchers may be able to present policy-makers with a typology of different kinds of enclosure movements, and with a systematic discussion of the probable outcome of each kind of movement. Therefore, the spontaneous enclosure of the range by livestock owners may raise new problems, but may also permit new approaches to the development of the livestock industry in the arid and semi-arid areas in Africa. This paper seeks to highlight the effects and implications of using enclosures for rehabilitating degraded semi-arid rangelands and draw practical lessons to help us achieve increased restoration capability in the future.

Belgian soil inventory and monitoring incentives for the assessment of soil quality and soil degradation

The objective of this paper is to discuss the socio-economic aspects of land evaluation and to advance in the development of land evaluation as an ecological economics of soils. The principles of the FAO Framework are considered a sound basis but further emphasis is needed in the analysis of the land utilization types and in the quantification of inputs and outputs of the land-use system. We discuss the approaches developed in the field of economics for the analysis of soil resources. These approaches date back to the classic economists of the 19th century, who recognised the spatial variability of soil characteristics and their influence on the formation of rent. The development of ecological economics at the end of the 20th century builds a bridge for further dialogue as it calls for the availability of soil maps as accounts of the soil resources and for land evaluation as the methodology to account for the land-use types and for the fluxes of services and other outputs from the land-use system.