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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

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    We will mail you new results for this query: keywords==grondbewerking gericht op bodemconservering
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Invloed van vaste rijpaden op de bodem
Balen, D.J.M. van - \ 2017
BIOpraktijk
landbouw - biologische landbouw - akkerbouw - grondbewerking - bodemdeeltjes - bodemverdichting - bodemsamenstelling - bodemstructuur - grondbewerking gericht op bodemconservering - bodemkwaliteit - rijspoorverdichtingen - verdichting - agriculture - organic farming - arable farming - tillage - aggregates - soil compaction - soil composition - soil structure - conservation tillage - soil quality - tractor pans - compaction
Landbewerking: video over de invloed van vaste rijpaden op de bodem
3 vragen aan: Joanneke Spruijt, onderzoeker WUR (interview)
Spruijt, J. - \ 2015
Landbouwmechanisatie 66 (2015)4. - ISSN 0023-7795 - p. 9 - 9.
akkerbouw - grondbewerking gericht op bodemconservering - grondbewerking - kosten-batenanalyse - veldproeven - bodemvruchtbaarheid - bodemstructuur na grondbewerking - duurzaam bodemgebruik - opbrengst - arable farming - conservation tillage - tillage - cost benefit analysis - field tests - soil fertility - tilth - sustainable land use - outturn
Het antwoord op 3 vragen over Kosten en baten van NKG bewerking op basis van verschillende onderzoeken in Nederland
Grond bewerken op juiste snelheid : PPO 't Kompas
Praktijkonderzoek Plant & Omgeving, - \ 2015
Boerderij 100 (2015)27. - ISSN 0006-5617 - p. 82 - 85.
akkerbouw - toegepast onderzoek - lichte kleigronden - verstuiven - grondbewerking gericht op bodemconservering - mestinjectie - arable farming - applied research - silt loam soils - dusting - conservation tillage - soil injection
Op lichte gronden kan de akkerbouwer schade door stuiven of slemp voorkomen door een combinatie van maatregelen. Dat blijkt uit onderzoek van PPO en Aequator.
Niet-ploegen vergt anders denken
Meijering, Luuk ; Balen, D.J.M. van - \ 2014
Boerderij/Akkerbouw 99 (2014)26. - ISSN 0169-0116 - p. 4 - 7.
akkerbouw - cultuurmethoden zonder grondbewerking - proeven op proefstations - veldproeven - teeltsystemen - grondbewerking gericht op bodemconservering - bodemdichtheid - fysische bodemeigenschappen - biologische landbouw - gereduceerde grondbewerking - bodembiodiversiteit - groenbemesters - arable farming - no-tillage - station tests - field tests - cropping systems - conservation tillage - soil density - soil physical properties - organic farming - reduced tillage - soil biodiversity - green manures
Om het maximale voordeel uit niet-kerende grondbewerking te halen heeft de teler andere referenties nodig zegt Derk van Balen van het PPO agv. Op het biologische proefbedrijf Broekemahoeve wordt daarnaar gezocht. In het project Basis (Broekemahoeve Applied Soil Innovation Systems) worden alternatieve grondbewerkingssystemen getest en verbeterd, en landbouwkundige en milieukundige voor- en nadelen van deze systemen beoordeeld.
Water management for rainfed maize in semi-arid Zimbabwe
Nyakudya, I.W. - \ 2014
Wageningen University. Promotor(en): Leo Stroosnijder. - Wageningen : Wageningen University - ISBN 9789461738981 - 148
waterbeheer - zea mays - regenafhankelijke landbouw - akkerbouw - semi-aride klimaatzones - zimbabwe - grondbewerking gericht op bodemconservering - water management - rainfed agriculture - arable farming - semiarid zones - conservation tillage
You can’t eat your mulch and have it too : cropping system design and tradeoffs around biomass use for Conservation Agriculture in Cameroon and Madagascar
Naudin, K. - \ 2012
Wageningen University. Promotor(en): Ken Giller, co-promotor(en): E. Scopel. - S.l. : s.n. - ISBN 9789461734341 - 220
grondbewerking gericht op bodemconservering - teeltsystemen - dekgewassen - mulchen - rotaties - madagascar - conservation tillage - cropping systems - cover crops - mulching - rotations

Conservation agriculture is defined by three main principles: minimum soil disturbance, permanent soil cover and crop rotations. CA is promoted as a promising technology for Africa, but to date, only a small area under CA fully complies with the above three principles. CA has both short and long term effects on crop productivity and sustainability through the modification of various agroecological functions. These functions are related to the quantity of crop and cover crop biomass produced and kept as mulch. One of the main challenges in designing CA for smallholder farming systems in developing countries is the competing uses for biomass, in particular for feeding livestock. The main difficulties are linking the efficiency of agroecological functions to varying degrees of biomass export, and evaluating the performance of cropping systems at farm level, which is where the decisions are made. In North Cameroon the quantity of biomass produced in the field has been doubled by associating a cover crop with a cereal crop. Part of the biomass was consumed by cattle during the dry season but the quantity of mulch that remained on the ground had a positive impact on the cotton water balance in the driest part of North Cameroon. In the Lake Alaotra region of Madagascar, the soil cover in rice fields under CA can vary, from 30% to 84% even in the same type of field depending on the plant used as cover crop, the quantity of biomass produced and management of the residues. The range is even greater when different kinds of fields are taken into consideration. Of course, the different agroecological functions can be fulfilled to a greater or lesser extent depending on the amount of available biomass and the resulting soil cover. The relationship between the quantity of biomass and soil cover has been calculated for different kinds of residues. We used these relationships to explore the variability of soil cover that could be generated in farmers’ fields, and to estimate how much of the biomass could be removed to feed livestock while leaving sufficient soil cover. Our results showed that under farmers’ conditions in Madagascar, the production and conservation of biomass was not always sufficient to fulfill all the agroecological functions of mulch. For example, partial export of biomass to be used as forage might have no effect in terms of erosion control but may considerably reduce the efficiency of physical weed control. As the balance between the potential benefits of exporting biomass and the efficiency of agroecological functions varies depending on the constraints and goals of each farm, we chose to analyze the potential benefits of exporting aboveground biomass to feed cattle at farm level. To this end, we modeled different size farms in Madagascar to investigate the relation between raising dairy cows and efficient application of CA. Our aim was to explore trade-offs and synergies between combinations of CA practices (i.e. different amounts of biomass exported) and the size of dairy cow herds (varying biomass needs and animal production). Changing the percentage of soil cover in CA plots did not significantly modify total farm net income, as this was more influenced by the characteristics of the milk market. Overall, CA systems can be beneficial for dairy cow farmers thanks to the forage produced, although the milk market and thus the value of biomass for forage, has a major influence on the way CA can be implemented at field level. To explore the range of possible cropping systems in a given biophysical situation, we created a tool named PRACT (Prototyping rotation and association with cover crop and no till). We used this tool to organize expert knowledge on crops and cover crops, biophysical characteristics of fields and agronomic rules and to link them using Malagasy conditions. PRACT generate a list of cropping systems, i.e. crops and cover crops and their sequences over three years. These cropping systems are characterized by their potential agroecological functions and crop production. The cropping systems are first selected based on the biophysical requirements of plants, plant compatibility and agronomic rules. But all the systems are not suitable for every kind of farm. Consequently using PRACT outputs, a second selection of cropping systems can be made based on the characteristics of the cropping system, i.e. crop production and agroecological functions. In this way, the selected cropping systems can be reduced to a number that can reasonably be handled by technicians and farmers. Finally, we recommend a more rigorous definition and characterization of treatments when comparing CA to conventional systems to obtain a clearer view of the link between the impact of CA, crop rotations and the level of biomass production. Key words: conservation agriculture, cropping system design, optimization, cover crops, cotton, rice, Cameroon, Madagascar

Long-term effects of conservation soil management in Saria, Burkina Faso, West Africa
Zacharie, Z. - \ 2011
Wageningen University. Promotor(en): Leo Stroosnijder, co-promotor(en): A. Mando; B. Ouattara. - [S.l.] : S.n. - ISBN 9789085858362 - 142
bodembeheer - grondbewerking gericht op bodemconservering - bodemfauna - bodemeigenschappen - sorghum - rotaties - veldwaterbalans - afrika ten zuiden van de sahara - soil management - conservation tillage - soil fauna - soil properties - rotations - field water balance - africa south of sahara

The negative degradation spiral that currently leads to deteriorating soil properties in African drylands is a serious problem that limits food production and threatensthe livelihoods of the people. Nutrient depletion and water and wind erosion are the main factors in soil degradation in Africa. This thesis describes field research conducted from 2006 through 2008 to assess how changes in physical and hydrological soil properties, induced by differences in land management and macro-faunal biodiversity determine water and nitrogen use efficiencies in Burkina Faso. The methodology involved systematic soil sampling of selected treatments (including a fallow control) coupled with macro-fauna identification. Measurements were used to generate information on the effect of the long-term land management practices on soil properties and the different terms of the field water balance. Crop sampling (leaves, stem and grains) allowed determination of plant nutrient uptake and calculation of water and nitrogen use efficiency. Differences in soil properties between treatments were smaller than expected after so many years of applying the same soil management practice. Results indicate that long-term permanent cultivation result in a decrease in the quality of most soil properties when compared with the fallow. We also found that there are clear benefits from inclusion of cowpea in a rotation system due to its N fixation and deeper root system. Regarding soil fauna, long-term application of the same soil management practices resulted in specialization of the food type for the macro-fauna leading to less fauna diversity. Also, more diverse and abundant macro-fauna was discovered under superficially tilled plots compared to tractor plowed plots. The contribution of the soil fauna to aggregate building depends on the amount and type of organic material available to the fauna as well as the soil management regime. In spite of the amount of applied organic amendments used in our trials, the C-stock in the soil has decreased at a rate of 0.25 % per year, perhaps limiting macro-fauna activity. The 3-year average of the green water use efficiency (ratio T/P) was only 14% and the crop yield was also low due to less than optimal crop management. Results further suggest that systematic, rather than strategically timed, N applications (organic and/or mineral) are likely to lead to N losses. Synchronizing N fertilizer application with crop-N demand and accounting for residual Nitrogen will lead to higher N fertilizer use efficiency. Soil management practices, crop selection and fertilizer regime can have positive or negative impacts on water and nutrient use efficiency. Practices with positive impact should be encouraged in order to increase crop productivity and improve food security in Burkina Faso.

Telen zonder ploeg
Weide, R.Y. van der; Balen, D.J.M. van; Meuffels, G.J.H.M. - \ 2010
Kennisakker.nl 2010 (2010)13-10-2010.
minimale grondbewerking - cultuurmethoden zonder grondbewerking - grondbewerking gericht op bodemconservering - bodemstructuur - groenbemesters - teeltsystemen - bodembeheer - akkerbouw - minimum tillage - no-tillage - conservation tillage - soil structure - green manures - cropping systems - soil management - arable farming
De laatste jaren is er wereldwijd, maar ook in Nederland in de landbouw meer interesse ontstaan voor de niet kerende grondbewerking (in de rest van dit artikel NKG genoemd). Deze toename in belangstelling is tweeledig. In dit artikel de mogelijkheden en noodzaak van NKG-technieken.
Technieken opheffen ploegzool 2008-2009: Gediepploegde grond Flevoland
Paauw, J.G.M. - \ 2009
Lelystad : PPO AGV - 19
mechanisatie - ploegen - diepploegen - diepe grondbewerking - grondbewerking - cultivateren - grondbewerking gericht op bodemconservering - regen - waterverzadiging - gronddruk - banden - mechanization - ploughs - deep ploughing - deep tillage - tillage - chiselling - conservation tillage - rain - waterlogging - ground pressure - tyres
In de praktijk zijn er op agrarische bedrijven steeds vaker problemen met wateroverlast. Dit komt o.a. door steeds extremere regenbuien, maar ook door de schaalvergroting. De machines worden steeds zwaarder en er kan tegenwoordig onder nattere omstandigheden gewerkt (geoogst) worden. Dit komt de structuur van de grond niet ten goede. Deze afnemende structuur wordt zowel in de bouwvoor als in de ondergrond waargenomen. Dit leidt tot plasvorming en lang nat blijven van de grond. Uiteraard pleegt dit een aanslag op het opbrengend vermogen van de grond. De bedrijven die te maken hebben met wateroverlast ervaren dat ook zelf. Hoewel de agrarische sector zich steeds meer zorgen maakt, is er niemand die de ontwikkelingen tegen kan houden
Het fundament is gelegd : de plus- en minpunten van niet-ploegen
Balen, D.J.M. van - \ 2009
Ekoland 29 (2009)6. - ISSN 0926-9142 - p. 25 - 27.
biologische landbouw - grondbewerking gericht op bodemconservering - cultuurmethoden zonder grondbewerking - rotaties - groenbemesters - organic farming - conservation tillage - no-tillage - rotations - green manures
Conservation agriculture - niet meer ploegen in combinatie met groenbemesters - is bezig aan een opmars. In Nederland, maar ook elders in de wereld. Circa 95 miljoen hectare worden met name in de VS, Brazilië en Argentinië op deze manier beteeld. Om de consequenties van deze werkwijze te onderzoeken, werd een proef gestart op de Broekemahoeve van PPO-AGV in Lelystad
Niet meer ploegen : Grote en langdurige proef niet-kerende grondbewerking
Tonjes, J. ; Balen, D.J.M. van - \ 2009
Nieuwe oogst / Magazine gewas 5 (2009)12. - ISSN 1871-093X - p. 12 - 13.
grondbewerking gericht op bodemconservering - cultuurmethoden zonder grondbewerking - onkruiden - bodembiologie - organische stof - bodemtemperatuur - conservation tillage - no-tillage - weeds - soil biology - organic matter - soil temperature
Niet meer ploegen. Om te weten wat de bodem doet, hoe het onkruid zich gedraagt en hoeveel energie het scheelt, ligt er nu een grote proef. Onderzoekers uit Lelystad willen de proef het liefst meer dan 10 jaar laten lopen
'Stop met ploegen'
Faber, J.H. - \ 2008
Kennis Online 2008 (2008)nov. - p. 5 - 5.
grondbewerking - grondbewerking gericht op bodemconservering - bodemfauna - bodembiologie - minimale grondbewerking - duurzame landbouw - tillage - conservation tillage - soil fauna - soil biology - minimum tillage - sustainable agriculture
In andere landen doen boeren het al: hun land bewerken zonder ploeg. Goed voor het milieu, voor duurzame landbouw, en zeker goed voor het bodemleven. Het ministerie van LNV zou in Nederland experimenten met niet-kerende grondbewerking moeten stimuleren, vindt bodemonderzoeker Jack Faber
Soil quality and farm profitability: A win-win situation
Pulleman, M.M. ; Hellin, J. ; Flores Velázquez, D. ; López Báez, W. - \ 2008
LEISA : ILEIA newsletter for low-external-input and sustainable agriculture 24 (2008)2. - ISSN 1569-8424 - p. 6 - 8.
grondbewerking gericht op bodemconservering - bodembescherming - maïs - cimmyt - mexico - latijns-amerika - conservation tillage - soil conservation - maize - latin america
Farmers are more likely to adopt and adapt improved soil management strategies if their efforts lead to an immediate economic benefit. An encouraging policy environment, as well as farmer organisation also stimulates the adoption of conservation practices. In Mexico, farmers are adapting their maize-based cropping systems to conservation agriculture, leading to both higher profits and soil conservation.
Ploegloze grondbewerking : toename capiciteit en lager brandstofverbruik met spitters en cultivatoren : thema industriegroenten
Meuffels, G.J.H.M. - \ 2007
Nieuwe oogst / Magazine gewas 3 (2007)16. - ISSN 1871-093X - p. 16 - 16.
groenteteelt - industrie - gewaskwaliteit - gewasopbrengst - mechanisatie - grondbewerking gericht op bodemconservering - bodembescherming - brandstofverbruik - spitfrezen - cultivators - landbouwtechniek - vegetable growing - industry - crop quality - crop yield - mechanization - conservation tillage - soil conservation - fuel consumption - rotary diggers - agricultural engineering
Door gestegen brandstofkosten en schaalvergroting kijken agrariërs kritisch naar het uitvoeren van de hoofdgrondbewerking met ploeg. Praktijk Onderzoek Plant en Omgeving (PPO) onderzocht het effect van ploegloze grondbewerking op opbrengst en kwaliteit bij diverse gewassen
Conservation tillage and nutrient management in dryland farming in China
Wang Xiaobin, - \ 2006
Wageningen University. Promotor(en): U.D. Perdok; Oene Oenema, co-promotor(en): Willem Hoogmoed. - [S.l. ] : S.n. - ISBN 908504488X - 209
grondbewerking gericht op bodemconservering - dry farming - bodemvruchtbaarheid - tarwe - maïs - kunstmeststoffen - oogstresten - regen - voedingsstoffenbalans - china - nutrientenbeheer - conservation tillage - soil fertility - wheat - maize - fertilizers - crop residues - rain - nutrient balance - nutrient management
Net zo goed als ploegen
Paauw, J.G.M. - \ 2005
Boerderij/Akkerbouw 90 (2005)7. - ISSN 0169-0116 - p. 8 - 9.
grondbewerking - grondbewerking gericht op bodemconservering - ploegen als grondbewerking - frezen als grondbewerking - woelen - erosiebestrijding - opbrengst - kwaliteit - werktuigen - akkerbouw - veehouderijbedrijven - demonstraties (vertoning) - limburg - tillage - conservation tillage - ploughing - rotary cultivation - ripping - erosion control - outturn - quality - implements - arable farming - livestock enterprises - demonstrations
Erosiebeperkende grondbewerking met boerenmachines in Zuid-Limburg kan het gangbare ploegen vervangen. Uit proeven blijkt geen verschil in opbrengst - wel in effect op erosie
Strijd tegen erosie: drijfmest, vanggewas en directzaai
Laarhoven, G.C.P.M. van - \ 2003
Praktijkkompas. Rundvee 17 (2003)1. - ISSN 1570-8586 - p. 20 - 21.
erosiebestrijding - grondbewerking gericht op bodemconservering - maïs - teelt - cultuurmethoden - erosion control - conservation tillage - maize - cultivation - cultural methods
Uit dit onderzoek bleek dat alternatieve methoden van grondbewerking zoals directzaai de kans op erosie en nitraatuitspoeling verminderen.
Delivering the Goods : Scaling out Results of Natural Resource Management Research
Harrington, L. ; White, J. ; Grace, P. ; Hodson, D. ; Hartkamp, A.D. ; Vaughan, C. ; Meisner, C. - \ 2002
Ecology and Society 5 (2002)2. - ISSN 1708-3087
milieubeheer - hulpbronnenbeheer - grondbewerking gericht op bodemconservering - geografische informatiesystemen - simulatiemodellen - technologieoverdracht - mexico - zuid-azië - zuidelijk afrika - environmental management - resource management - conservation tillage - geographical information systems - simulation models - technology transfer - south asia - southern africa
To help integrated natural resource management (INRM) research "deliver the goods" for many of the world's poor over a large area and in a timely manner, the authors suggest a problem-solving approach that facilitates the scaling out of relevant agricultural practices. They propose seven ways to foster scaling out: (1) develop more attractive practices and technologies through participatory research (2) balance supply-driven approaches with resource user demands, (3) use feedback to redefine the research agenda, (4) encourage support groups and networks for information sharing, (5) facilitate negotiation among stakeholders, (6) inform policy change and institutional development, and (7) make sensible use of information management tools, including models and geographic information systems (GIS). They also draw on experiences in Mesoamerica, South Asia, and southern Africa to describe useful information management tools, including site similarity analyses, the linking of simulation models with GIS, and the use of farmer and land type categories
Tillage for soil and water conservation in the semi-arid Tropics
Hoogmoed, W. - \ 1999
Agricultural University. Promotor(en): U.D. Perdok; Leo Stroosnijder. - Wageningen : Wageningen University [etc.] - ISBN 9789058080264 - 184
grondbewerking - verzegelen - losmaken - korsten - bodembescherming - grondbewerking gericht op bodemconservering - infiltratie - west-afrika - brazilië - tillage - sealing - loosening - crusts - soil conservation - conservation tillage - infiltration - west africa - brazil
<p>Soil tillage is the manipulation of soil which is generally considered as necessary to obtain optimum growth conditions for a crop. In the same time the resulting modification of soil structure has serious implications for the behaviour of the soil to erosive forces by water and wind. In Chapter 1 an introduction is given to the most important aspects: the objectives of tillage, the conflicting requirements set to tillage, the characteristics of soil and water conservation in the semi-arid tropics, and the nature of tillage research including modelling.</p><p>Chapter 2 treats in detail the characteristics of the soils often found in the semi-arid tropics: the SCH soils (sealing, crusting and hardsetting). Sealing and crusting causes problems with emergence of seedlings and with infiltration. The hardsetting soils are difficult to manage, particularly when tillage has to be performed with limited energy inputs. Physical characteristics and low organic matter contents are primarily responsible for SCH behaviour.</p><p>In case 1, research undertaken in Mali is reported. Sandy soils of the Sahel area, mainly cropped to millet <em>(Pennisetum glaucum (L.) R.Br.)</em> are very sensitive to crust formation. These crusts were found to strongly reduce infiltration capacity. On the typically gently (1-3%) fields 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. Crust formation and its effect on the infiltration rate was studied in experiments using a rainfall simulator are discussed. On untilled soils the presence of a crust is a permanent feature, and the effect of superficial tillage on crust disturbance disappeared quickly under subsequent rainfall. It was established that rainfall characteristics (aggressiveness, intensity) play a key role in crust formation.</p><p>Research reported in case 2 was carried out in Niger. Here, important processes of soil structural changes under rainfall were assessed, to obtain a basis for a proper development of improved soil management methods. Soil and rainfall characteristics of a millet growing area close to Niamey, were determined. Laboratory tests showed a confirmation of what was observed in the field, namely that the coarse sandy soil of the area shows a mechanical behaviour which is extremely dependent on the moisture content at the time of soil handling. Therefore, the workability range is very narrow. Special tillage under wet conditions, resulting in smearing of the surface layer caused a condition which was more resistant to wind erosion. In an extension of the analyses reported in case 1, it was found the rainfall in this region is aggressive; even small storms may fall with high intensities.</p><p>The major rainfall characteristics of the Sahel differ significantly from those of other semi-arid areas (such as India). The erratic rainfall pattern in combination with the sandy nature of the soil in the region studied, leads to an extremely small number of days available for planting millet, on average around 11 for the season. Therefore, time-efficiency of soil preparation and planting methods is even more important than a positive effect on SWC and crop emergence aspects.</p><p>Chapter 3 gives a review of the various tillage systems as they may be applied for soil and water conservation, based the soil characteristics and on different mechanization levels.</p><p>A study carried out in Brazil is presented in case 3. In a highly mechanized farming situation, erosion problems on sloping, red soils in the state of Paraná are high. Conventional tillage is based on the use of heavy disk ploughs and repeated passes with disk harrows in order to prepare a seedbed. This system causes severe erosion damage because of reduced infiltration rates and unstable topsoil. The zero-tillage system is a promising and realistic alternative, but is not suited for all farms in the state (small fields, high capital investment for equipment required, lacking knowledge and experience of farmers). The possibilities for the use of chisel ploughs (as an alternative between these two systems) on wheat stubble in a wheat-soybean rotation were investigated.</p><p>Experiments showed that, compared to conventional tillage systems with disc implements, chisel ploughing left more plant residue at the surface. Except for the duckfoot type, the chisels were able to penetrate down to the bottom of a compacted layer at 12-20 cm depth. In addition, fuel consumption was significantly lower than disc ploughing and slightly higher than heavy disc harrowing. The capacities of the chisel ploughs were comparable to the heavy disc harrow. On the other hand, weeds and large amounts of straw may cause considerable practical difficulties and require adequately dimensioned chisel ploughs. Thus when applying the alternative tillage, adapted sowing equipment, able to cope with surface residue is required.</p><p>In case 4, studies on the agronomic effect of tillage systems fit for animal traction in West Africa are reported. Crop establishment is an important yield factor for pearl millet in the Sahel. Therefore, a series of experiments was conducted to determine the effects of seed size, depth and method of planting, millet variety, tillage, and soil fertilization upon seedling emergence, crop establishment, and yield. All experiments were conducted on a sandy Psammentic Paleustalf in Niger. Three millet varieties were studied, and for all of these, out of a range of sowing depths from 1 to 7 cm, a sowing depth of 3-5 cm resulted in the highest percentage emergence, the highest above-ground biomass, and most secondary roots. High soil temperatures are common during establishment, typical maximum temperatures at a depth of 1 cm exceed 46 °C. It was found that the adverse effects of wind erosion and these high temperatures were least when sowing in hills (the traditional hand-method); establishment, crop stand survival, and yield were better under hill planting than drilling seed.</p><p>Tillage of the field before sowing increased initial stands and their survival, the latter also depending on fertility. Thus, improved crop yields result from better stand survival and higher yields per hill. Fertilizer application (17 kg ha <sup>-1</SUP>P and 40 kg ha <sup>-1</SUP>of N) caused a threefold increase in grain yields. Ridging without prior tillage and ploughing increased grain and stover yields two- to three-fold. In combination with fertilizer application, sixfold yield increases were obtained. In view of the time limitations, ridging without prior tillage was preferable to ploughing, as it is a much faster operation giving equally good results in terms of crop establishment and yield.</p><p>Chapter 4 deals with simulation models for soil and water conservation and the difficulties of modelling tillage effects. A review of the most important models currently used in SWC is presented with a brief indication if and how tillage is incorporated in these models. Various options of approaching tillage effects by modelling are given.</p><p>In case 5, the development and application of a model simulating the role of tillage in SWC is presented. The data used are mainly from the situation prevailing in the West African Sahel and Sudan zone, characterized by a low input (particular N and P) rainfed farming system, growing cereal crops such as millet. Two types of soil tillage are distinguished: tillage aimed at water conservation (by increasing infiltration and/or surface roughness) and tillage aimed at weed control. Various scenarios are evaluated by combining simulation models for plant production (WOFOST) and soil water movement (SWATRE), developed and adapted for application in these regions. Based on simulations of 35 years of weather data, it was found that water conserving tillage <em>as such</em> has a very small yield-conserving effect because of the limitations set by the nutrient status. Elimination by tillage of the competition by weeds had a larger effect on the grain yield of a millet crop.</p><p>In case 6, the water balance for millet fields and for permanently crusted natural pastures is described, with special emphasis on the role of the crust in governing infiltration and runoff. This study was based on the same field experiments in Mali as described in case 1. It was tried to quantify the effect of tillage as it destroys the crust and increases the surface storage for rainwater. The crust-breaking effect was found to last for only a few rainshowers, but the increase of surface storage is more permanent. The effect of a tillage system on the water balance of a millet crop was calculated. From this calculation it was concluded that tied ridges, giving a surface storage of 20-30 mm, could completely prevent runoff, compared to about 50% loss under the conventional system. Such a savings would allow earlier sowing and thus prolong the vegetative growth by as much as 20 days, which might increase the average millet yield (500 kg ha <sup>-1</SUP>) by 40%.</p><p>In Chapter 5, the prospects for development of tillage systems for the difficult SCH soils are discussed. Analysis of the various options shows that no-tillage is not a solution for the semi-arid tropics with hardsetting soils. It also can be argued that the introduction of animal traction in situations with purely handlabour, in many cases is not feasible, and notwithstanding all other problems, tillage by tractors should be investigated as a serious option.</p>
The economics of soil conservation in developing countries: the case of crop residue mulching
Erenstein, O.C.A. - \ 1999
Agricultural University. Promotor(en): A. Kuyvenhoven; Leo Stroosnijder; H.A.J. Moll. - S.l. : S.n. - ISBN 9789058080899 - 301
erosie - bodembescherming - mulchen - oogstresten - innovatie adoptie - technologie - grondbewerking gericht op bodemconservering - economische evaluatie - ontwikkelingslanden - mexico - erosion - soil conservation - mulching - crop residues - innovation adoption - technology - conservation tillage - economic evaluation - developing countries
The study contributes to the search for a methodology to assess soil conservation, particularly in developing countries. The study first assesses the economics of soil conservation in general - with special emphasis on the relationships between technology, economic analysis and policy implications. The quantification and valuation of soil erosion and soil conservation are highly controversial and present considerable analytical challenges that have been tackled in varying ways. By implication, government intervention is controversial too - and has typically been unsuccessful. This has direct implications for both the development of conservation technology and the implementation of conservation interventions.</p><p>The study subsequently assesses the economics of one particular technological conservation option: crop residue mulching (also known as conservation tillage). An analytical framework is developed to assess the socio-economics of the technology in developing countries. The technology assessment framework follows a stepwise expanding analysis along a three-tier hierarchy: crop production, the farm household and the institutional setting. This results in a private and a social assessment of the technology, and the formulation of corresponding policy implications. The framework is applied in <em>ex ante</em> , <em>ex post</em> and partial analyses of crop residue mulching in different settings in Mexico and Central America. Conclusions are drawn regarding the technology assessment framework and crop residue mulching.</p><p>The author can be contacted at:<A HREF="mailto:olaf_erenstein@usa.net">olaf_erenstein@usa.net</A></p><p>The study is also published in the Mansholt Studies, Wageningen University and can be ordered from Backhuys Publishers, Leiden, the Netherlands (<A HREF="http://www.backhuys.com">http://www.backhuys.com</A>, or<A HREF="mailto:info@backhuys.com">info@backhuys.com</A>).</p>
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