Moving precision agriculture to a new dimension: the ARS/CSU precision farming project at Wiggins, Colorado

Presented at the Central Plains irrigation short course and exposition on February 17-18, 1998 at the Camino Inn in North Platte, Nebraska.Includes bibliographical references.As more producers become aware of precision farming technology they are asking how it can improve productivity and profitability. There is a vast array of claims, beliefs, and testimony, yet little quantitative data to answer this question. Multi-disciplinary field scale research is needed in precision farming to answer the questions of productivity and profitability. The Agricultural Research Service and Colorado State University have begun a multi-disciplinary research program that focuses on developing a clearer scientific understanding of the causes of yield variability. We intend to develop decision support systems for site specific management. A team of 15 scientists covering the areas of soil fertility, crop production, weed science, entomology, plant pathology, system engineering, remote sensing, GIS, irrigation engineering, agricultural economics and statistics has started a project to develop a better understanding of precision agriculture in Colorado. They are collecting and analyzing data from 2 center pivot irrigated fields Cooperating farmers manage all the crop production operations and provide yield maps of the corn grown on the fields (175 and 130 ac.). The important variables for crop production have been sampled at several different intervals. Both fields have been sampled at a grid spacing of 250 feet. More intensive sampling has been done by various disciplines in smaller areas at a variety of scales down to 50 feet. Concurrent work, in cooperation with industry, is developing center pivot and linear move irrigation systems to apply variable site specific rates of chemicals and water. We will discuss the project and the various data layers being collected

Crop Fertilization on Coast Prairie and Coastal Bend Soils.

4 p

Crop Fertilization on Coast Prairie and Coastal Bend Soils.

4 p

Crop Fertilization on Coast Prairie and Coastal Bend Soils.

4 p

Grazing and No-Till Cropping Impacts on Nitrogen Retention in Dryland Agroecosystems

As the world\u27s population increases, marginal lands such as drylands are likely to become more important for food production. One proven strategy for improving crop production in drylands involves shifting from conventional tillage to no-till to increase water use efficiency, especially when this shift is coupled with more intensive crop rotations. Practices such as no-till that reduce soil disturbance and increase crop residues may promote C and N storage in soil organic matter, thus promoting N retention and reducing N losses. By sampling soils 15 yr after a N tracer addition, this study compared long-term soil N retention across several agricultural management strategies in current and converted shortgrass steppe ecosystems: grazed and ungrazed native grassland, occasionally mowed planted perennial grassland, and three cropping intensities of no-till dryland cropping. We also examined effects of the environmental variables site location and topography on N retention. Overall, the long-term soil N retention of \u3e18% in these managed semiarid ecosystems was high compared with published values for other cropped or grassland ecosystems. Cropping practices strongly influenced long-term N retention, with planted perennial grass systems retaining \u3e90% of N in soil compared with 30% for croplands. Grazing management, topography, and site location had smaller effects on long-term N retention. Estimated 15-yr N losses were low for intact and cropped systems. This work suggests that semiarid perennial grass ecosystems are highly N retentive and that increased intensity of semiarid land management can increase the amount of protein harvested without increasing N losses

AGU hydrology days 2008

2008 annual AGU hydrology days was held at Colorado State University on March 26 - March 28, 2008.Includes bibliographical references.Water is the most production limiting factor for dryland cropping systems in semiarid Great Plains environments. Evaporation is responsible for the greatest amount of water loss and management practices such as notill have been adopted to reduce evaporative losses. Less is known about the magnitude of water loss due to runoff. An objective of this study is to estimate an expected range in rainfall runoff in dryland agroecosystems and the potential for improving precipitation use with management practices that reduce runoff. Another objective was to estimate soil-water erosion associated with runoff. The approach coupled an analysis of historical hourly rainfall intensity data and field measurements of runoff and erosion from dryland agroecosystems study sites in Sterling and Stratton, Colorado. Rainfall analysis was used to determine the frequency and quantity of high intensity rainfall expected to generate runoff. Runoff was estimated based on assumed fractions of high intensity rainfall for variable management and climate conditions and based on field observations at the same sites. Runoff was estimated to range between 8 mm for drought years and management with good surface protection to 80 mm for years with above average precipitation and management with poor protection of the soil surface. There is the potential to capture as much as 60 mm of precipitation through improved management practices, a quantity that can increase crop yield and profitability. Annual rates of erosion by water were estimated to range between 1 and 9 Mg ha⁻¹. Under management with poor surface protection, soil erosion rates in dryland cropping systems are too high to sustain crop production, while management that protects the soil surface and reduces the probability of runoff is an effective means of soil erosion control. Residue management achieved through no-till or minimum till practices is the most effective means of soil erosion control and sustaining dryland agriculture in the semi-arid Great Plains will depend on adoption of these practices

Grazing and No-Till Cropping Impacts on Nitrogen Retention in Dryland Agroecosystems

As the world\u27s population increases, marginal lands such as drylands are likely to become more important for food production. One proven strategy for improving crop production in drylands involves shifting from conventional tillage to no-till to increase water use efficiency, especially when this shift is coupled with more intensive crop rotations. Practices such as no-till that reduce soil disturbance and increase crop residues may promote C and N storage in soil organic matter, thus promoting N retention and reducing N losses. By sampling soils 15 yr after a N tracer addition, this study compared long-term soil N retention across several agricultural management strategies in current and converted shortgrass steppe ecosystems: grazed and ungrazed native grassland, occasionally mowed planted perennial grassland, and three cropping intensities of no-till dryland cropping. We also examined effects of the environmental variables site location and topography on N retention. Overall, the long-term soil N retention of \u3e18% in these managed semiarid ecosystems was high compared with published values for other cropped or grassland ecosystems. Cropping practices strongly influenced long-term N retention, with planted perennial grass systems retaining \u3e90% of N in soil compared with 30% for croplands. Grazing management, topography, and site location had smaller effects on long-term N retention. Estimated 15-yr N losses were low for intact and cropped systems. This work suggests that semiarid perennial grass ecosystems are highly N retentive and that increased intensity of semiarid land management can increase the amount of protein harvested without increasing N losses