Elevation map-based variable rate poultry litter application is a promising method in cotton production

Escherichia coli transported in surface runoff from dissolution of applied poultry litter is a major variable in assessing fecal contamination of streams. However, the relative magnitude of the E. coli concentration from a specific poultry litter application and relative to the time lag between litter application and rainfall are not completely understood. This research investigated E. coli transport in runoff on fourteen, 2 m by 2 m pastureland plots. Poultry litter was manually applied (4,942 kg/ha) in twelve plots followed by artificial rainfall with intensities equivalent to 2-yr and 5-yr storm events. Rainfall was applied in duplicate plots immediately after poultry litter application and 24 and 120 hr after litter application. Experiments were also conducted on two control plots without poultry litter application. Surface runoff was collected using a flume installed in a trench. Escherichia coli was quantified from sampled runoff and used as an indicator of fecal contamination by the most probable number (MPN) technique. No significant differences were observed in average event mean concentrations (EMCs) relative to storm intensity. Statistically significant differences were observed in average EMCs relative to time lag between litter application and rainfall. A nonlinear relationship was observed between average Escherichia coli EMC and time lag, with the EMC decreasing between 0 hr (1.6x105 MPN/100 mL) and 24 hr (1.3x104 MPN/100 mL) and then increasing at 120 hr (4.3x104 MPN/100 mL). Escherichia coli were always detected in the control plots (average EMC of 6.8x103 MPN/100 mL) indicating the presence and transport of fecal bacteria from sources independent of the immediate poultry litter application. Even though poultry litter application may increase E. coli concentrations in runoff, other sources of fecal contamination serve as a significant component of the total E. coli EMC, especially as the time lag between litter application and rainfall events increase.

Inadequate and less vigorous crop stand is a constraint to adoption of conservation tillage in cotton (Gossypium hirsutum L.) production. We evaluated the effects of tillage (conventional till, mulch‐till, no‐till), cropping system (cotton–winter fallow, cotton–winter rye, Secale cereale L.), and N source and rate (ammonium nitrate and poultry litter; 0, 100, and 200 kg N ha−1) on cotton seedling emergence on a Decatur silt loam soil (Typic Paleudults) in northern Alabama, from 1996 to 1998. Cotton seedling counts under no‐till were 40 to 150% greater than those under conventional till at 1 and 2 d during seedling emergence. Cotton–winter rye cropping system had 14 to 50% greater seedling counts than cotton–winter fallow cropping during the first 4 d of emergence in 1998. Poultry litter source of N gave 17 to 50% greater cotton seedling counts than ammonium nitrate during the first 4 d of emergence in 1998. In all these cases, the differences progressively narrowed down by the 4th day of seedling emergence. Cotton seedling counts were significantly correlated to cotton growth parameters and lint yield, especially in the drier year (1998). These results were attributed to soil moisture conservation during seedling emergence. Our results show that conservation tillage improved cotton germination, emergence, dry matter, and lint yield. Therefore, no‐till with winter rye cover cropping and poultry litter can be used for achieving early cotton seedling emergence and growth in the U.S. cotton belt where dryland cotton production systems are on the increase and safe disposal of poultry litter is becoming an environmental problem.

The application of poultry (<i>Gallus gallus domesticus</i>) litter to agricultural soils may exacerbate losses of trace elements in runoff water, an emerging concern to water quality. We evaluated trace elements (arsenic [As], mercury [Hg], selenium [Se], and zinc [Zn]) in surface runoff and leachate from an agricultural soil with and without poultry litter application. Litter from a commercial operation was applied by three methods—broadcast application, subsurface placement, and broadcast application followed by disking—to no-till soils with a history of receiving litter. Soil monolith lysimeters (61 by 61 by 61 cm)(24 by 24 by 24 in) were extracted from each of the treatments and subjected to rainfall simulation (1 hour, 61 mm h⁻¹ [2.4 in hr⁻¹]) 15 and 42 days after litter application. Broadcasting poultry litter significantly increased concentrations (mg L⁻¹) and loads (g ha⁻¹) of As and Zn in runoff during the first event relative to other application methods. Notably, incorporating litter, either by disking after broadcasting or by subsurface placement, lowered As and Zn in runoff to near background levels by the second event, and there were no significant differences in As and Zn between any of the treatments. While Hg and Se were detected in runoff, they likely derived from edaphic sources as they were not detected in the litter nor did they differ significantly between treatments. Results point to poultry litter as a temporary source of some trace elements to runoff. This source can be readily controlled by adjusting application method.

Land application of poultry litter to pasture elevates the concentration of phosphorus in surface runoff, and it is becoming an increasing problem in sensitive water bodies. The objectives of this study were to assess the effects of soil test phosphorus (STP), surface application of poultry litter, rainfall/runoff sequences, and time after litter application on dissolved reactive phosphorus (DRP) in surface runoff from pasture in a greenhouse experiment using rainfall simulation. Treatment factors were poultry litter at a rate of 0.0 and 6.7 Mg ha-1, low and high STP, and three rainfall/runoff sequences (RRS). The latter refers to runoff-producing rainfall events starting from day 1, day 4, and day 7 after litter application. The study also included a rainfall simulation study of pasture field plots to investigate the effects of poultry litter and time after application on DRP in surface runoff, which was used to corroborate the greenhouse study. In both studies, runoff samples were taken at the end of 30 min of continuous runoff. Treatment effects on DRP concentrations in surface runoff were analyzed using ANOVA procedures using an alpha = 0.05. For the greenhouse study, poultry litter application, RRS, and time after litter application were found to have a highly significant effect on DRP concentration in surface runoff. Poultry litter had a significant effect on DRP concentrations in surface runoff until 18 days after litter application compared to the controls. Between 18 and 32 days after litter application, the effect on DRP became insignificant for any level of STP or rainfall sequence. A rainfall event without runoff reduced DRP concentration in the first surface runoff events by more than 50%. For the field plot study, DRP decreased rapidly with time, thereby corroborating the greenhouse study. The effect of poultry litter on DRP became statistically insignificant sometime between 35 and 161 days after application.

Cotton acreage in the Coastal Plain of the Southeast has increased in recent years. The soils in this region are sandy and typically have a low retention capacity for sulfate S. A 3-yr (1993-1995) field test was conducted in south Alabama on a Lucy loamy sand (loamy, kaolinitic, thermic Arenic Kandiudults) to evaluate the response of cotton (Gossypium hirsutum L.) to the source, rate, and timing of S fertilizer applications. Sulfur was broadcast preplant as either ammonium sulfate, elemental S, potassium sulfate, potassium thiosulfate, or K-Mg-sulfate at rates of 0, 10, 20 and 40 lb S/acre. Additionally, ammonium sulfate was applied at first square to evaluate timing effects. Lint yields were increased each year and they peaked at a rate of approximately 20 lb S/acre on this Lucy Is soil. Averaged across sources, 20 lb S/acre increased lint yields by an average of 21% as compared with the no S check treatment. Lint yields were not affected by time of S application in 1993 or 1995, but a preplant application of S increased yield compared with S applied at first square in 1994. The response to time of S application was attributed to heavy rainfall that was received soon after the first square application of S. Sources of S did not affect lint yield in 1993 or 1995, but ammonium sulfate and K-Mg-sulfate produced slightly higher yields than those of other sources in 1994, an extremely wet growing season. Lint quality, as measured by high volume instrumentation (HVI), was not affected by any S treatment in 1993 or 1994. In 1995, fiber length increased with S rate, but the differences among sources were inconsistent. Results of this test suggest that cotton produced on sandy Coastal Plain soils that are low in S may require annual applications of 20 lb S/acre to ensure high yields. The S should be applied preplant, although delaying application to first square should not limit yields. For lint production, differences among commercial S fertilizer sources should be minimal.

Assessment of repeated application of poultry litter on phosphorus and nitrogen dynamics in loblolly pine: Implications for water quality

Poultry litter (PL) application and double cropping are management practices that could be used with conservation tillage to increase yields compared with conventional mono-cropping systems. The objective of this study was to evaluate winter wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] yield response to PL alone and combinations of PL and inorganic N versus inorganic N alone when applied to the winter wheat in a double-cropping system. The study was conducted from 2014 to 2016 at two locations on a Marvyn loamy sand and a Lucedale fine sandy loam. Experimental design at each location was a randomized complete block design. Fertility treatments for winter wheat included an unfertilized control (PL₀N₀), inorganic N fertilizer (120 lb acre–¹, PL₀N₁₂₀), PL at the rate of 40 lb N acre–¹ plus 80 lb acre–¹ inorganic N (PL₄₀N₈₀), PL at the rate of 80 lb N acre–¹ plus 40 lb acre–¹ inorganic N (PL₈₀N₄₀), and PL at the rate of 120 lb N acre–¹ (PL₁₂₀N₀). An unfertilized winter fallow treatment was also included to enable a comparison of yield between the mono- and double-cropped soybean. A combination of PL and inorganic N resulted in wheat yields comparable to those with inorganic N alone while PL alone yielded less. Double-cropping soybeans with winter wheat tended to improve soybean yield when compared with mono-cropped soybeans planted on the same date; however soybean yield was not consistently enhanced by the residual PL nutrients applied to wheat when compared with N fertilizer only treatment.

Effect of Poultry Litter to Water Ratios on Extractable Phosphorus Content and its Relation to Runoff Phosphorus Concentrations

Alternative management of broiler chicken (Gallus gallus domesticus) litter in cotton (Gossypium hirsutum L.) production is needed to enhance soil fertility, crop nutrient utilization, and lint yield. This 4‐yr study compared the growth, lint yield, and soil quality in cotton production systems fertilized with pelletized poultry litter (PPL) subsurface band applied at the rate of 6.7 Mg ha−1 (≈122 kg available N ha−1), inorganic N fertilizer (urea ammonium nitrate, UAN solution) injected at the recommended rate of 128 kg N ha−1, and unfertilized control. Drip irrigation was used as main plot, flue gas desulfurization (FGD) gypsum was broadcast applied and used as subplot, and fertilization treatment was used as sub‐subplot (2 × 2 × 3). Although leaf chlorophyll content, leaf area index and total aboveground biomass were lower (P &lt; 0.05) with PPL than inorganic N, lint yield did not differ between these treatments in 2010 and 2011. However, lint yield was greater in PPL than inorganic N fertilizer treatment by approximately 6% in 2012 and 21% in 2013. Averaged across years, lint yield was 5% greater with PPL than inorganic N fertilizer (1378 vs. 1303 kg ha−1). Cotton lint yield was not influenced by FGD gypsum or irrigation. Applying PPL significantly enhanced soil fertility, improved soil aggregate stability, minimized postharvest residual NO3–N concentration in the soil profile and may provide growers with an alternative nutrient management strategy for cotton.Core Ideas Subsurface band placement minimizes nutrient loss. Subsurface band placement of pelletized poultry litter increases nutrient utilization. Pelletized poultry litter improves soil quality by enhancing soil organic C.

The direct application of poultry litter (PL) in the soil leads to some environmental problems. Poultry litter biochar (PLB) produced through the pyrolysis process under limited oxygen supply at 400 °C for 10 min, and nutrients were analyzed for both PL and PLB. Both PL and PLB were applied in the soil at 1, 2, and 3% (w/w) along with control. Ipomoea aquatica was grown in earthen pots for 60 days to evaluate the response of both PL and PLB. After pyrolysis of PL, the nutrients content (total N, K, S, Ca, Mg, and Zn), pH, electric conductivity, and organic carbon in PLB were found to be increased than those of PL except for P. Plant height significantly increased by 14.3, 23.3, 20.1%; and 17.8, 34.4, 32.4% after the application of 1, 2, and 3% PL and PLB, respectively, as compared to the control. Plant fresh weight significantly increased by 70.4, 124.6, and 124.7% and 53.3, 134.3, and 200.4% compared to the control after the application of PL and PLB at 1, 2, and 3%, respectively. Increased plant height and fresh weight can be ascribed mostly to the capacity of PL and PLB as a source of nutrients for plant uptake. The significantly higher yield was observed at 3% PLB application. Compared to the PL, plant height and fresh weight increased by 18.2 and 33.68%, respectively, at 3% PLB application. PLB rather than PL might be a promising organic amendment for maintaining sustainable agriculture.

Excessive poultry litter (PL) application in forage systems poses environmental risks. This study evaluated the potential of plant growth-promoting rhizobacteria (PGPR) to reduce PL dependence in annual ryegrass ( Lolium multiflorum ) and tall fescue ( Lolium arundinaceum ) production. Four PL rates (0%, 50%, 75%, 100% of 168 kg N/ha) were tested with and without a bacillus-based PGPR consortium ( B. altitudinis AP18, B. subtilis AP278, B. safensis AP280, and Lysinibacillus macroides AP282) in a randomized complete block design with six replicates. PGPR had no significant effect on seedling emergence but significantly enhanced plant height, tiller number, shoot and root biomass, and root traits across PL rates. These impacts were more pronounced in annual ryegrass. Ryegrass under 50% and 75% PL + PGPR was 3.8% and 8.66% taller than 100% PL alone. Tall fescue under 75% PL + PGPR was 2.84% taller than 100% PL, while 50% PL was slightly shorter but not significant. Tiller numbers under 50–75% PL + PGPR matched those of 100% PL in both grasses. Shoot biomass at 50% and 75% PL + PGPR in ryegrass (2.23 and 2.18 g/container) and tall fescue (1.08 and 0.44 g/container) was similar to 100% PL (2.02 and 0.44 g/container). PGPR at 50–75% PL increased root biomass by 10–12% in ryegrass and 4–17% in tall fescue. Additionally, 50–75% PL + PGPR improved root traits in the 0.51–2.00 mm and &gt; 2 mm diameter classes compared to 100% PL. PGPR with reduced PL supports sustainable forage production.

Long‐term tillage and manure application can alter a soil's ability to sequester nutrients and mineralize C and N. A laboratory incubation study (C and N mineralization) evaluated the long‐term impact of poultry litter (PL) application (&gt;10 yr) and tillage practice (&gt;25 yr). Soil chemical properties (pH, total C, total N, and Mehlich‐1 extractable P, K, Ca, and Mg) were also assessed. Soil was collected (0–5‐, 5–10‐, and 10–20‐cm depths) from continuous soybean [ Glycine max (L.) Merr.] and corn ( Zea mays L.) systems managed under conventional tillage (CT) or no‐till (NT) with either PL or inorganic fertilizer (IF) applications. The study was located in northeast Alabama on a Hartsells fine sandy loam (a fine‐loamy, siliceous, subactive, thermic Typic Hapludult). Poultry litter and NT increased soil nutrients (N, P, K, Ca, and Mg), primarily at the 0‐ to 5‐cm depth. No‐till concentrated nutrients near the soil surface as opposed to the more even distribution seen under CT. The NT‐PL treatment had higher soil C for corn and soybean (2.25 and 1.83 g kg −1 C, respectively), followed by NT‐IF (1.73 and 1.11 g kg −1 C, respectively). Carbon and N mineralization was higher at the 0‐ to 5‐cm depth for NT and CT compared with lower depths. Long‐term PL application increased C and N mineralization more than IF. As depth increased, more C and N mineralization occurred under CT due to plow layer mixing. Results indicated that long‐term tillage with PL application can increase soil C and N mineralization, nutrient retention, and organic matter.

Phosphorus (P) concentration in surface waters from non-point agricultural sources is an increasing resource management concern. This study was conducted at Overton, Texas, on a Bowie fine sandy loam (fine-loamy, siliceous, thermic, Plinthic Paleudults) to evaluate cool-season legumes for P uptake following poultry litter (PL) application rates on spring vegetables. Treatments were PL rate (0, 1X, 2X, 4X) and a commercial blend (CB) for comparison. Cool-season legumes, consisting of crimson clover, berseem clover, hairy vetch, and red clover, were the subplots. The vegetable crop in Spring 1995 was watermelon. The 1X PL rate was 2.2 t·ha-1 and the CB was 44.8N-0P-32.5K kg·ha-1. Dry matter yield was decreased by the 4X PL rate. Plant P concentration increased linearly as PL rate was increased. The greatest P uptake (4.1 kg·ha-1) was at the 2X rate. Hairy vetch had the greatest yield (1,875 kg·ha-1), plant P concentration (0.53%), and P uptake (9.6 kg·ha-1). PL rate increased soil P concentration at all depths. The least amount of P accumulation was from CB and was equal to the control. Hairy vetch appears to have the capability of removing a greater amount of P and reducing soil concentration when compared to the other legume species tested.

Poultry litter is generated in large quantities in the same southeastern U.S. states where cotton (Gossypium hirsutum L.) is a dominant field crop, but is rarely used as a primary cotton fertilizer partly because of lack of adequate management recommendations. This research was conducted to determine adequate rates of broiler litter and whether supplementation with inorganic N would be necessary for optimum cotton lint yield and fiber quality. The research was conducted from 2002 to 2004 on two commercial farms representing conventional‐till (CT) and no‐till (NT) systems. The treatments consisted of an unfertilized control, a farm standard (STD) fertilized with inorganic fertilizers, and broiler litter of 2.2, 4.5, and 6.7 Mg ha−1 in an incomplete factorial combination with 0, 34, or 67 kg ha−1 N as urea–ammonium nitrate solution (UAN). Litter without supplemental UAN–N increased yield by 23 to 110 kg lint ha−1 for every 1.0 Mg ha−1 litter under both CT and NT. The often‐recommended litter rate of 4.5 Mg ha−1 was not adequate to increase yield to be equivalent to that of the STD that received 101 to 135 kg ha−1 as UAN. It was necessary to supplement this or the other litter rates with 34 or 67 kg ha−1. UAN–N to support yield equal to or greater than the yield of the STD. The most consistently well‐performing treatment under both tillage systems in all years was the 4.5 Mg ha−1 litter supplemented with 67 kg ha−1. UAN–N. Lint yield was highly correlated (r2 = 0.83–0.97) with applied total plant‐available N (NTPA) under both systems. Fiber quality, fiber length and micronaire in particular, also responded to NTPA, but the responses were smaller than lint yield. Litter when adequately supplemented with UAN–N did not adversely affect fiber quality. These results show broiler litter as much as 4.5 Mg ha−1 should be supplemented with inorganic N fertilizers when used as a primary cotton fertilizer and when the expected yield is ≈1700 kg ha−1 under CT and ≈1500 kg ha−1 under NT.

This study aimed to simulate the spatiotemporal variation in cotton (Gossypium hirsutum L.) growth and lint yield using a remote sensing-integrated crop model (RSCM) for cotton. The developed modeling scheme incorporated proximal sensing data and satellite imagery. We formulated this model and evaluated its accuracy using field datasets obtained in Lamesa in 1999, Halfway in 2002 and 2004, and Lubbock in 2003–2005 in the Texas High Plains in the USA. We found that RSCM cotton could reproduce the cotton leaf area index and lint yield across different locations and irrigation systems with a statistically significant degree of accuracy. RSCM cotton was also used to simulate cotton lint yield for the field circles in Halfway. The RSCM system could accurately reproduce the spatiotemporal variations in cotton lint yield when integrated with satellite images. From the results of this study, we predict that the proposed crop-modeling approach will be applicable for the practical monitoring of cotton growth and productivity by farmers. Furthermore, a user can operate the modeling system with minimal input data, owing to the integration of proximal and remote sensing information.