Economic Feasibility of Variable‐Rate Nitrogen Application Utilizing Site‐Specific Management Zones

Abstract

Variable-rate technology (VRT) has been developed to variablyThe potential for improved profitability due to variapply crop inputs to manage in-field variability. Although growers have able-rate N application depends on identifying areas in begun to adopt VRT, its profitability is uncertain in N management. the field where additional N inputs will increase revenue The objective of this study was to assess the economics of uniform vs. variable-rate N fertilizer application under two N application scenarios on a scale that is greater than the added costs and/or (farmer vs. custom applications). On-farm studies were conducted on identifying areas where reducing N inputs will decrease two continuous corn (Zea mays L.) fields in northeastern Colorado costs on a scale that is greater than potential revenue under furrow and center-pivot irrigation during the 2000 and 2001 reduction correlated with lower grain yield (Snyder et al., growing seasons. The N management strategies were uniform, grid-based, 1999). Therefore, the economic feasibility of variable-rate site-specific management zone-constant yield goal (SSMZ-CYG) and N application is focused on whether increases in gross site-specific management zone-variable yield goal (SSMZ-VYG). "Profit revenue or decreases in N input costs outweigh the added and loss" software was used to analyze the economics of each N cost of technologies or services needed for variable-rate N management strategy and determine which N strategy was most profitapplication ( Ferguson et al., 1999;Thrikawala et al., 1999). Thrikawala et al. (1999) reported that the profitability N fertilizer (6-46%) was used with the SSMZ-VYG N management strategy when compared with uniform N management. Net returns from of variable-rate N application increased above that of the SSMZ-VYG N management strategy were $18.21 to $29.57 ha Ϫ1 uniform N application as area and in-field soil variability more than uniform N management. Results of this study suggest variincreased. However, additional information and appliable-rate N application utilizing site-specific management zones are cation expenses are involved when managing spatial more economically feasible than conventional uniform N application. variability occurring throughout a field. Review of literature suggested that most studies incorporated the information costs (i.e., soil sampling, developing variable-rate able. Results from three site-years consistently indicated that less total

Responsive in-season nitrogen management for cereals

“…Another major factor contributing to low NUE in current strategies has been uniform application rates of fertilizer N to spatially variable landscapes, even though numerous field studies have indicated economic and environmental justification for spatially variable N applications in many agricultural landscapes (Mamo et al, 2003;Hurley et al, 2004;Koch et al, 2004;Scharf et al, 2005;Shahandeh et al, 2005;Lambert et al, 2006;Hong et al, 2007). Uniform applications within fields discount the fact that N supplies from the soil, crop N uptake, and response to N are not the same spatially (Inman et al, 2005).…”

Simulation des seuils de rentabilité économique de techniques d’application localisée des pesticides

“…Ils se limitent au gain que représentait la diminution des quantités d'intrant ou aux marges brutes. De plus, ces expérimentations ont porté sur des cultures spécifiques, blé le plus souvent, (Duval et al, 2007), ou maïs (Koch et al, 2004) et/ou un type d'intrant tel que l'azote en général (Dailey et al, 2006 ;De Vuyst et Halvorson, op. cit.…”

Estimating Soil Solution Nitrate Concentration from Dielectric Spectra Using Partial Least Squares Analysis

“…Although precise application of N is attainable through variable-rate technology, a great challenge facing its widespread utilization is the lack of a robust and fast measurement system for real-time monitoring of NO 3 dynamics in soil water (Zhang et al, 2002). In situ monitoring of NO 3 -N concentrations can help to optimize the application of N-rich fertilizers, reduce the risk of NO 3 -N leaching to water bodies, and evaluate the effi ciency of best management practices targeted on the improvement of N uptake by plants during the growing season (Roberts et al, 2002(Roberts et al, , 2010Koch et al, 2004). Traditional methods for measuring soil NO 3 concentration are accurate, but at the same time they are labor intensive, time consuming, expensive, and destructive, which limits their application in real-time in situ monitoring for large areas.…”