A synthesis of multi-disciplinary research in precision agriculture: site-specific management zones in the semi-arid western Great Plains of the USA

Abstract

Researchers from Colorado State University, in collaboration with scientists from the United States Department of Agriculture (USDA), initiated a long-term multidisciplinary study in precision agriculture in 1997. Site-specific management zones (SSMZ) were investigated as a means of improving nitrogen management in irrigated maize cropping systems. The objective was to develop precise nutrient management strategies for semi-arid irrigated cropping systems. This study was conducted in five fields in northeastern Colorado, USA. Two techniques for delineating management zones were developed and compared: SSMZ and yield-based management zones (YBMZ). Nitrogen uptake and grain yield differences among SSMZs were compared as were soil properties. Both management zone techniques were used to divide fields into smaller units that were different with regard to productivity potential (e.g., high zones had high productivity potential while low zones had low productivity potential). Economic analysis was also performed. Based on grain yield productivity, the SSMZs performed better than the YBMZ technique in most cases. Grain yield and N uptake between the low and high productivity management zones were statistically different for most site-years and N fertilizer rates (p \ 0.05). Soil properties helped to explain the productivity potential of the management zones. The low SSMZ was markedly different from the high SSMZ based on bulk density, organic carbon, sand, silt, porosity and soil moisture. Net returns ranged from 188 to 679 USD ha -1 . In two out of three site-years the variable yield goal strategy resulted in the largest net returns. In this study, the SSMZ approach delineates areas of different productivity accurately across the agricultural fields. The SSMZs are different with regard to soil properties as well as grain yield and N uptake. Site-specific management zones are an inexpensive and pragmatic approach to precise N management in irrigated maize.

QuickBird satellite versus ground-based multi-spectral data for estimating nitrogen status of irrigated maize

“…The N application rates were based on various site-specific management zones that were previously delineated on this field as part of a large multi-disciplinary project. Details of the management zone delineation process can be found in Khosla et al (2002Khosla et al ( , 2008. The N application amounts were determined by the N rate algorithm according to Mortvedt et al (1996) for each management zone.…”

Management zones definition using soil chemical and physical attributes in a soybean area

“…According to KHOSLA et al (2008), who conducts a research related to PA viability, there are some unknowns from producers that ultimately hinder its use in a more expressive way. Among the questions asked by the researcher, there are included some as: 1) Is it possible to determine the spatial variability of attributes in a less costly way?…”

Recent advances in precision (target) conservation

“…By integrating remote sensing with precision conservation tools, the effectiveness of conservation practices can be improved and the impact of agriculture on the environment can be reduced. Management zones can also be integrated when applying precision conservation techniques to increase nitrogen use efficiency and reduce nitrate leaching losses without decreasing yields, as shown by earlier work from Khosla et al (2002Khosla et al ( , 2008, , and Inman et al (2007Inman et al ( , 2008. Galzki et al (2011) found that LIDAR provides very precise terrain attributes that can be used to identify environmentally sensitive areas for targeted conservation practices (e.g., grassed waterways, buffer strips, and/or the retirement of land from cultivation or application of conservation tillage).…”