Willem B. Hoogmoed

Bio: Willem B. Hoogmoed is an academic researcher from Wageningen University and Research Centre. The author has contributed to research in topics: Tillage & No-till farming. The author has an hindex of 26, co-authored 56 publications receiving 2766 citations.

Soil water retention as affected by tillage and residue management in semiarid Spain

Abstract: Conservation tillage preserves soil water and this has been the main reason for its rapid dissemination in rainfed agriculture in semiarid climates. We determined the effects of conservation versus conventional tillage on available soil water capacity (AWC) and related properties at the end of 5 years of management on a clay loam calcic soil ( Calcic Haploxerept ) in semiarid northern Spain. No-tillage with (NTSB) and without stubble burning (NT), reduced chisel-plough tillage (RT) and conventional tillage with mouldboard plough (MT) were compared in rainfed barley monoculture. Bulk density ( ρ b ), organic matter content (OM), soil water retention (SWR) at matric potentials of 0 to −1500 kPa, and soil water content (SWC) were determined in the driest year of the 5-year study period. Soil OM in the upper 0.15 m was significantly higher (13%) under NTSB, NT and RT than under MT. Soil ρ b in the upper 0.15 m under NT and NTSB was greater than under RT and MT, but at a depth of 0.15–0.30 m was greater under RT than under the other treatments. Reorganisation of pore sizes due to tillage treatments affected AWC. Under RT and MT the largest percentage of the total soil porosity was occupied by pores >9 μm (equivalent pore diameter), in accordance with lower ρ b . Available water capacity was greater with NT than with RT and MT. Higher SWC under conservation tillage systems (NT, NTSB and RT) than under MT was attributed mainly to greater AWC and to the mulching effect of crop residues. Crop yield in the driest year of the 5-year period was lowest under MT whereas no differences among treatments were found over the 5-year period. Stubble burning did not affect AWC nor barley yield. Tillage had a greater impact on soil properties and on crop yield than crop residue management.

Sensing soil properties in the laboratory, in situ, and on-Line: A review

Abstract: Since both the spatial and vertical heterogeneities in soil properties have an impact on crop growth and yield, accurate characterization of soil properties at high sampling resolution is a preliminary step in successful management of soil-water-plant system. Conventional soil sampling and analyses have shown mixed economical returns due to the high costs associated with labor-intensive sampling and analysis procedures, which might be accompanied with map uncertainties. Therefore, the conventional laboratory methods are being replaced or complemented with the analytical soil sensing techniques. The objective of this chapter is to review different soil sensing methods used to characterize key soil properties for management of soil-water-plant system. This will cover laboratory, in situ in the field, and on-line measurement methods. This review chapter is furnished with an overview of background information about a sensing concept, basic principle and brief theory, various factors affecting the output of the sensor, and justification of why specific soil properties can be related with its output. The literature review is succeeded with an integration and analysis of findings in view of application in the precision agriculture domain. Potentials and limitations of current sensor technologies are discussed and compared with commonly used state-of-the-art laboratory techniques. As sensing is commonly addressed as a very technical discipline, the match between the information currently collected with sensors and those required for site-specific application of different inputs, and crop growth and development is discussed, highlighting the most accurate method to measure a soil property for a given application.

Crust formation on sandy soils in the Sahel I. Rainfall and infiltration

Abstract: Sandy soils of the Sahel area in West Africa, mainly cropped to millet (Pennisetum typhoides) are very sensitive to crust formation Crusts strongly reduce infiltration capacity In this area most fields are gently sloping (1–3%) and hence runoff is a widespread phenomenon; on the average 25% of the rain (mainly in the form of a few large storms during the rainy season) is lost by runoff The causes of crust formation and its effect on the infiltration rate are discussed On untilled soils the presence of a crust is a permanent feature Rainfall characteristics play a key role in crust formation Major rainfall characteristics of the Sahel differ significantly from those of other semi-arid areas

Macropores and water flow in soils

Abstract: This paper reviews the importance of large continuous openings (macropores) on water flow in soils. The presence of macropores may lead to spatial concentrations of water flow through unsaturated soil that will not be described well by a Darcy approach to flow through porous media. This has important implications for the rapid movement of solutes and pollutants through soils. Difficulties in defining what constitutes a macropore and the limitations of current nomenclature are reviewed. The influence of macropores on infiltration and subsurface storm flow is discussed on the basis of both experimental evidence and theoretical studies. The limitations of models that treat macropores and matrix porosity as separate flow domains is stressed. Little-understood areas are discussed as promising lines for future research. In particular, there is a need for a coherent theory of flow through structured soils that would make the macropore domain concept redundant.

Soil Erosion and Conservation

Abstract: This is a review of worldwide land degradation problems. Four themes are emphasized: delineating and estimating the magnitude of soil erosion, quantifying erosion and sedimentation impacts on land productivity, establishing quantitative values for erosion-causing parameters, and implementing global and regional soil and water conservation programs. Papers deal with both developing and developed countries and illustrate how erosion control techniques used in developed countries can or cannot be applied in developing countries.

Temperature increase reduces global yields of major crops in four independent estimates

Abstract: Wheat, rice, maize, and soybean provide two-thirds of human caloric intake. Assessing the impact of global temperature increase on production of these crops is therefore critical to maintaining global food supply, but different studies have yielded different results. Here, we investigated the impacts of temperature on yields of the four crops by compiling extensive published results from four analytical methods: global grid-based and local point-based models, statistical regressions, and field-warming experiments. Results from the different methods consistently showed negative temperature impacts on crop yield at the global scale, generally underpinned by similar impacts at country and site scales. Without CO2 fertilization, effective adaptation, and genetic improvement, each degree-Celsius increase in global mean temperature would, on average, reduce global yields of wheat by 6.0%, rice by 3.2%, maize by 7.4%, and soybean by 3.1%. Results are highly heterogeneous across crops and geographical areas, with some positive impact estimates. Multimethod analyses improved the confidence in assessments of future climate impacts on global major crops and suggest crop- and region-specific adaptation strategies to ensure food security for an increasing world population.