Browsing by Autor "Dirk Raes"

Now showing 1 - 13 of 13

Agro-climatic suitability mapping for crop production in the Bolivian Altiplano: A case study for quinoa
(Elsevier BV, 2006) Sam Geerts; Dirk Raes; Ligia García; Carmen Del Castillo; Wouter Buytaert
Agroclimatic constraints for rainfed agriculture in the Bolivian Altiplano
(Elsevier BV, 2007) María Cruz García-González; Dirk Raes; Sven‐Erik Jacobsen; Thibauld Michel
Comment on Araya et al.: “Simulating yield response to water of Teff (Eragrostis tef) with FAO's AquaCrop model” [Field Crops Research (2010) 116, 196–204]
(Elsevier BV, 2010) Sam Geerts; Dirk Raes; Ligia García; Roberto Miranda; Jorge Cusicanqui; Cristal Taboada; Jorge Mendoza; Ruben Huanca; Armando Mamani; Octavio Condori
Could deficit irrigation be a sustainable practice for quinoa (Chenopodium quinoa Willd.) in the Southern Bolivian Altiplano?
(Elsevier BV, 2008) Sam Geerts; Dirk Raes; Ligia García; Octavio Condori; Judith Mamani; Roberto Miranda; Jorge Cusicanqui; Cristal Taboada; Edwin Yucra; Jean Vacher
Crop water use indicators to quantify the flexible phenology of quinoa (Chenopodium quinoa Willd.) in response to drought stress
(Elsevier BV, 2008) Sam Geerts; Dirk Raes; Ligia García; Jorge Mendoza; Ruben Huanca
Dynamics of reference evapotranspiration in the Bolivian highlands (Altiplano)
(Elsevier BV, 2004) Ligia García; Dirk Raes; R. G. Allen; Carlos Herbas
Economic assessment at farm level of the implementation of deficit irrigation for quinoa production in the Southern Bolivian Altiplano
(Spanish National Research Council, 2013) Jorge Cusicanqui; Koen Dillen; María Cruz García-González; Sam Geerts; Dirk Raes; Erik Mathijs
In the Southern Bolivian Altiplano recent research has suggested to introduce deficit irrigation as a strategy to boost quinoa yields and to stabilize it at 2.0 ton ha-1. In this study we carried out an economic assessment of the implementation of deficit irrigation at farm level using a hydro-economic model for simulating profit for quinoa production. As input of the model we worked with previously developed farms typology (livestock, quinoa and subsistence farms), simulated quinoa production with and without irrigation using AquaCrop model, and calculated yield response functions for four different climate scenarios (wet, normal, dry and very dry years). Results from the hydro-economic model demonstrate that maximum profit is achieved with less applied irrigated water than for maximum yield, and irrigated quinoa earned more profit than rainfed production for all farms types and climate scenarios. As expected, the benefits of irrigation under dry and very dry climate conditions were higher than those under normal and wet years, and benefits among farms types were higher for quinoa farms. In fact, profit of irrigated quinoa might be stabilized at around BOB 6500 ha-1 (about USD 920) compared with the huge differences found for rainfed conditions for all climate scenarios. Interestingly, the economic water productivity, expressed in terms of economic return for amount of applied irrigated water (BOB mm-1), reached the highest values with intermediate and low level of water availability schemes of deficit irrigation for all climate scenarios.
Evapotranspiration analysis and irrigation requirements of quinoa (Chenopodium quinoa) in the Bolivian highlands
(Elsevier BV, 2003) Ligia García; Dirk Raes; Sven‐Erik Jacobsen
Farmers' willingness to adopt irrigation for quinoa in communities of the Central Altiplano of Bolivia
(Universidad Católica Boliviana San Pablo, 2011) Cristal Taboada; Armando Mamani; Dirk Raes; Erik Mathijs; Ligia García; Sam Geerts; Jere L. Gilles
Quinoa is considered a strategic crop because it is well adapted to the adverse abiotic conditions of the Bolivian Altiplano; however, the average yield is low. Previous studies have demonstrated that quinoa yield would increase with deficit irrigation technology. Nevertheless, to irrigate quinoa is not a normal practice in the farming systems of the Altiplano. This paper examines the main factors that determine the attitude of farmers towards adopting deficit irrigation using a sample of 137 surveys in seven communities of the Central Altiplano. Statistic analysis demonstrates that the most important factors influencing farmers' willingness for irrigation adoption are the acreage planted with quinoa, quantity of surplus production for trading, and having irrigation experience. Also, the age and education level were important to know willingness to adopt a new technology. Therefore, deficit irrigation is more likely to be performed in area where farmers own larger fields and where there is already certain type of irrigation.
Introducing deficit irrigation to stabilize yields of quinoa (Chenopodium quinoa Willd.)
(Elsevier BV, 2008) Sam Geerts; Dirk Raes; Ligia García; Jean Vacher; Richard Mamani; Jorge Mendoza; Ruben Huanca; Bernardo Morales; Roberto Miranda; Jorge Cusicanqui
Modeling the potential for closing quinoa yield gaps under varying water availability in the Bolivian Altiplano
(Elsevier BV, 2009) Sam Geerts; Dirk Raes; María Cruz García-González; Cristal Taboada; Roberto Miranda; Jorge Cusicanqui; Teddious Mhizha; Jean Vacher
Simulating Yield Response of Quinoa to Water Availability with AquaCrop
(Wiley, 2009) Sam Geerts; Dirk Raes; Ligia García; Roberto Miranda; Jorge Cusicanqui; Cristal Taboada; Jorge Mendoza; Ruben Huanca; Armando Mamani; Octavio Condori
The modeling of yield response to water is expected to play an increasingly important role in the optimization of crop water productivity (WP) in agriculture. During 3 yr (2004–2007), field experiments were conducted to assess the crop response to water stress of quinoa ( Chenopodium quinoa Willd.) in the Bolivian Altiplano (4000 masl) under different watering conditions (from rain fed, RF, to full irrigation, FI). Crop physiological measurements and comparisons between simulated and observed soil water content (SWC), canopy cover (CC), biomass production, and final seed yield of a selected number of fields were used to calibrate the AquaCrop model. Subsequently, the model was validated for different locations and varieties using data from other experimental fields and from farmers' fields. Additionally, a sensitivity analysis was performed for key input variables of the parameterized model. AquaCrop simulated well the decrease of the harvest index (HI) of quinoa in response to drought during early grain filling as observed in the field. Further‐on, the procedure for triggering early canopy senescence was deactivated in the model as observed in the field. Biomass WP (g m −2 ) decreased by 9% under fully irrigated conditions compared with RF and deficit irrigation (DI) conditions, most probably due to severe nutrient depletion. Satisfactory results were obtained for the simulation of total biomass and seed yield [validation regression R 2 = 0.87 and 0.83, and Nash‐Sutcliff efficiency (EF) = 0.82 and 0.79, respectively]. Sensitivity analysis demonstrated the robustness of the AquaCrop model for simulation of quinoa growth and production, although further improvements of the model for soil nutrient depletion, pests, diseases, and frost are also possible.
Using AquaCrop to derive deficit irrigation schedules
(Elsevier BV, 2010) Sam Geerts; Dirk Raes; María Cruz García-González