Henry Sintim
Department of Crop and Soil Sciences; University of Georgia
Introduction
There has been considerable volatility in commodity prices over the past decade. Cotton price surged in 2022, but input costs, such as chemical, fertilizer, and fuel costs, also increased. Profit margins could be maintained if input costs increase proportionally. However, there is a disproportionate increase in chemical, fertilizer, and fuel costs, relative to cotton prices, requiring efficient management systems to maintain profit margins. The figure below shows the USDA-NASS monthly cotton prices and the monthly price index of chemicals, fertilizers, and fuels from January 2016 to July 2025. The price index used 2011 as the base year (100% index). The average cotton price in 2024 was $0.73/lb, and the chemical, fertilizer, and fuel index prices for the same year were 117%, 104%, and 89.7%, respectively. This represents a 13.5% cotton price increase, and chemical, fertilizer, and fuel index price increases of 8.67%, 44.4%, and 61.3%, respectively, when compared to the prices in 2016. Compared to the price in 2024, the average cotton price from January to July 2025 has decreased by 17.5%, whereas the chemical and fertilizer index prices have slightly increased by 0.18% and 2.22%, respectively. The fuel index price decreased marginally (by 2.4%).
Soil management operations incur production costs through expenses like fuel, labor, machinery depreciation, and inputs such as fertilizers and soil amendments. While some costs are associated with immediate field operations, other aspects, like degraded soil, can lead to long-term, indirect production losses and costs. As such, soil management operations must be carefully planned, taking into account the trade-offs between increased productivity, economic profitability, and long-term sustainability. It is also important to tailor management practices to production and environmental conditions. Soils in Georgia are predominantly Ultisols, which are characterized as highly weathered soils with clay-enriched subsoil, are acidic, and have relatively low native fertility and cation exchange capacity. The soils have low organic matter due to climatic conditions (well-distributed and intensive rainfall events, with hot summers and mild winters) that facilitate rapid mineralization of organic matter and crop residues returned to the soil. Thus, the need to sustain soil health conditions is very critical in Georgia. The USDA-NRCS principles to manage and improve soil health include minimizing soil disturbance, maximizing biodiversity, maximizing soil cover, and maximizing living roots. The newsletter highlights integrated nutrient management and strategic tillage systems as potential soil management operations to enhance productivity, profitability, and long-term stewardship of farmland in Georgia cotton production.
Integrated nutrient management
Integrated nutrient management is a sustainable agriculture approach that combines organic, inorganic, and biological nutrient sources to maintain soil fertility, optimize nutrient supply for crops, and improve productivity while minimizing environmental impacts. Conventional nutrient management relies on inorganic fertilizer application to meet crop nutritional needs, with routine fertilizer recommendations for cotton calling for the application of N, P, K, S, and B, and occasional application of Ca and Mg when liming to correct for soil pH. Harvest removes nutrients from the field in a way comparable to mining minerals, and thus, deliberate replacement is needed to sustain soil fertility.
In Georgia, the integration of poultry litter into nutrient management for cotton could be a way to save costs, sustain crop productivity, and improve soil fertility. Poultry litter is replete with secondary and micronutrients, as well as soil microbes that will enrich the biological health of soils. Also, poultry litter contains organic compounds that act as natural chelating agents. These natural chelators in poultry litter help to stabilize micronutrients in the soil, influencing plant uptake and protecting plants from toxicity. It is important to note that excessive application of poultry litter can lead to high metal concentrations in the soil over time and cause problems. In a typical cotton-peanut-corn rotation, poultry litter can be applied during the cotton and corn phases of the rotation, allowing for excess nutrients from the poultry litter to be removed during the peanut phase. Periodic soil testing is also recommended to monitor and ensure safe soil nutrient levels. Poultry litter has been routinely applied at 2 tons/ac (on a dry basis) in a number of studies in cotton with success. The applications were made not more than two weeks before planting, and assumed 50% N and 80% of all remaining nutrients would be available in the first season. The nutrient content of poultry litter can vary depending on the type of bird, feed type and ration, number and duration of growouts, and mode of storage and handling of the litter. It is highly recommended that the nutrient content of poultry litter be analyzed before determining application rates and value.
The table below shows the average nutrient composition (on a dry basis) of poultry litter sourced from different broiler and layer houses in Georgia. As can be seen, broiler litter tends to have more nutrient content than layer litter. The nutrient content of the litter can be used to estimate its fertilizer equivalence value. Converting the reported nutrient composition of the litter to 30% moisture, and basing on the average DTN fertilizer prices from 2023 to 2025 ($439/ton for UAN-32; $775/ton for DAP, and $527/ton for Potash), the total fertilizer value would be $88.1/ton for the broiler litter and $45.6/ton for the layer litter. The fertilizer equivalence value reported did not account for secondary and micronutrients. Currently, poultry litter can be obtained for $35-55/ton; thus, it would be economically advantageous to integrate broiler litter rather than layer litter. The UGA-AESL broiler litter fertilizer worksheet is a useful tool to help calculate the value of broiler litter based on prevailing retail selling prices of inorganic N, P, and K fertilizers and the nutrient content from the laboratory analyses (https://aesl.ces.uga.edu/calculators/BroilerLitter/).
Strategic tillage system
Tillage is a land preparation practice that entails the mechanical process of loosening and aerating the soil. Tillage improves soil tilth by breaking up soil crust and increasing soil porosity, which is important to encourage root growth and overall crop productivity. The figure shows soil resistance to penetration before and after tillage under different management systems. The CT and CT+Int were under conventional tillage systems, and the ST and ST+Int were under a strip tillage system. As can be seen, soil depth to compaction (300 PSI or 2 MPa) increased more under the CT and CT+Int systems. Tillage is also a very important weed control measure. However, intensive tillage systems over the long term will pulverize the soil and enhance soil erosion, leaching, and the rapid mineralization of organic matter. Thus, there has been a great interest in conservation tillage systems. Conservation tillage is a general term based on the principles of (a) minimum disturbance of soil, (b) retention of crop residues on the soil surface, and (c) reduced or no traffic on the field. The minimum soil disturbance helps to reduce the breakdown of soil organic matter and crop residues. Also, the retention of crop residues on the soil surface under conservation tillage acts as organic mulch and protects the soil against raindrop impact, which otherwise would have disintegrated and promoted soil erosion. Tillage incurs fuel, labor, and machinery depreciation costs; thus, reducing tillage saves production costs. If not properly implemented, however, conservation tillage can lead to soil compaction, extensive weed pressure, and nutrient stratification issues.
Strategic tillage is the targeted, occasional, and limited use of tillage implements in specific locations, depths, and times to address identified soil constraints while minimizing overall soil disturbance. In strategic tillage systems, a soil penetrometer can be used to monitor soil resistance to penetration, and tillage operations performed only when needed. Penetrometer readings above 300 indicate a soil compaction problem. Soil moisture has a major influence on soil penetrometer readings, and the recommendation is to measure soil resistance to penetration when soil moisture is at field capacity or soil moisture level after free drainage, typically a day after intensive rainfall. Also, avoid taking readings from compacted areas caused by traffic. It is a good practice to maintain consistency in tire traffic to avoid random compaction across a wider area of the field.
A number of studies have been conducted to assess the integration of different regenerative agricultural practices in Georgia. The results on cotton lint yield and return-on-investment (ROI) of the study conducted in 2023 and 2024 in Midville, GA, are shown. The management systems are (a) conventional tillage (abbreviated as CT), (b) strip tillage (abbreviated as RT), (c) strip tillage under cover crop (abbreviated as RT+CC), and (d) strip tillage under cover crop and with poultry litter as the organic amendment (abbreviated as RT+CC+PL). The reduced tillage was a one-time strip-tillage operation every year, and cereal rye was used as the cover crop. Treatment (d) received a 2 tons/ac rate of poultry litter, and based on the nutrient composition of the poultry litter, no additional inorganic fertilizer was applied. Adopting a strip tillage-only operation or strip tillage integrated with cover crop tended to affect the yield and ROI. However, integrating poultry litter minimized yield loss and sustained the ROI, which $149.8/ac ROI obtained in 2024. A true assessment of the value of poultry litter integration into the system is to compare treatment RT+CC and RT+CC+PL.
Conclusions
Efficient input management is critical to sustain cotton production, especially given the decline in cotton prices in recent months. Integrated nutrient management and strategic tillage systems were discussed as potential ways to save cost and sustain cotton productivity. Growers can use a soil penetrometer to monitor soil compaction to determine whether tillage operation is needed. Such an approach will ensure that conservation tillage is implemented only when needed, thereby avoiding compaction issues associated with transitioning into a conservation tillage system. It will also help save costs when the readings indicate no-tillage or a reduced tillage operation is all that is needed. In addition, the use of poultry litter in cotton could be a way to save costs, sustain crop productivity, and improve soil health. However, there is a need to periodically monitor soil nutrient levels to avoid accumulating excess nutrient levels that could cause production problems.