Browsing by Autor "Armando Mamani"

Now showing 1 - 3 of 3

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
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.
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.