Temporal and spatial variability of plant available N in the humid southeastern region United States often results within-field over- under- application this nutrient to cotton. Although ground-based canopy reflectance has potential quantify crop status real-time drive variable rate fertilizer applications, currently utilized vegetation indices fail correlate strongly with status. Therefore, objective study was examine relationships between across wavelengths calculated ratios prior at...

Changes in spatial and temporal variability yield estimation are detectable through plant biophysical characteristics observed at different phenological development stages of corn. A multispectral red-edge sensor mounted on an Unmanned Aerial Systems (UAS) can provide information with high resolution. Spectral analysis UAS acquired spatiotemporal images be used to develop a statistical model predict based stages. Identifying critical vegetation indices (VIs) significant spectral could lead...

Abstract The purpose of this study was to determine the effects tillage on corn ( Zea mays L.) total N uptake and recovery from 15 N‐depleted legume residue. A conventional (CT) variable introduced into a 7‐yr‐old no‐tillage (NT) in 1984 by moldboard plowing disking half each no plot having either residue (winter fallow) or hairy vetch Vicia villosa Roth.) cover. Prior year, situ vegetation removed replaced with fresh at comparable rate. In 1984, final cover 31 kg ha −1 greater CT than NT;...

The inclusion of legumes in cropping systems raises questions about their effectiveness as a N source. objective this study was to determine the effects tillage on legume cover crop decomposition and transformation dynamics fertilizer 15N. Nitrogen-15-labeled hairy vetch (Vicia villosa Roth.) residue or added soil cores contained open-ended Plexiglas tubes placed field. Vetch residues were either surface for notillage (NT), mixed with conventional (CT). In 1984, 15NH415NO3 applied at rates 0...

In‐season assessment of cotton ( Gossypium hirsutum L.) leaf N and K concentration using remote sensing techniques is needed to address spatial temporal variation these two nutrients. The objective this study was evaluate the effects varying availability on chlorophyll detection utilizing reflectance properties. Fertilizer rates 0, 45, 90, 135, 180 kg ha −1 in factorial combination with 0 112 were applied under field conditions. Recently matured leaves main stem collected at first bloom peak...

ABSTRACT Nondestructive assessment of cotton (Gossypium hirsutum L.) nitrogen (N) nutritional status could aid fertilizer recommendations by providing a rapid, easy, and inexpensive method detection. A greenhouse experiment with N rates equivalent to 40, 80, 120, 160 kg ha−1 was conducted determine the response in leaf reflectance chlorophyll meter readings varying levels. 50/50 blend masonry sand Marietta soil (fine-loamy, siliceous, thermic Fluvaquentic Eutrochrepts) used as potting media....

Crop reflectance using ground‐based sensors has the potential to provide information on crop N status in real‐time. However, unique physiological and structural characteristics of cotton ( Gossypium hirsutum , L.) complicate normalized difference vegetation index (NDVI)‐based inferences status. Therefore, objectives this study were (i) determine sensitivity selected resulting NDVI measurements different levels fertilizer N; (ii) relationships between biophysical measurements; (iii) compare...

Abstract The varying influence of the environment on N supply and demand dictates need for annually updated fertilizer recommendations. Currently, crop yield goal (CYG) methods are used by 34 land grant universities, including Mississippi State University, these do not consider environmental variations. This research tested efficacy CYG determining agronomic optimum rate (AONR) economic corn ( Zea mays L.) production. In total, 12 treatments in 2020 11 2021 were replicated four times over...

Efficient crop utilization of N and P derived from anaerobic swine ( Sus scrofa domesticus ) lagoon effluent is critical to minimizing offsite nutrient movement. The objective this study was determine the effects variable rates fertilizer on yield forage grasses an acid Vaiden silty clay (very fine, montmorillonitic, thermic, Vertic Hapludalf) alkaline Okolona (fine, Typic Chromudert). Treatments were multiple irrigations resulting in four 0 665 94 kg ha −1 yr P, respectively. Fertilizer...

In-season assessment of cotton (Gossypium hirsutum L.) leaf N and K concentration using remote sensing techniques is needed to address spatial temporal variation these two nutrients. The objective this study was evaluate the effects varying availability on chlorophyll detection utilizing reflectance properties. Fertilizer rates 0, 45, 90, 135, 180 kg ha−1 in factorial combination with 0 112 were applied under field conditions. Recently matured leaves main stem collected at first bloom peak...

Field experiments were conducted in 2009 and 2010 Louisiana Mississippi to evaluate ammonia volatilization loss subsequent effects on apparent nitrogen recovery efficiency (ANRE) grain yield for rice ( Oryza sativa L.). A semi‐open static chamber approach was used measure from multiple N sources applied 10 days before flood (dbf) at the rate of 168 kg ha −1 . Cumulative losses urea environments 19 33% compared 7% both environments. Urea + [N‐(n‐butyl) thiophosphoric triamide] (NBPT), NBPT...

Applying the optimum rate of fertilizer nitrogen (N) is a critical factor for field management. Multispectral information collected by active canopy sensors can potentially indicate leaf N status and aid in predicting grain yield. Crop Circle multispectral data were acquired with purpose measuring reflectance to calculate vegetation indices (VIs) at different growth stages. have considerable impact on yield profitability. The objectives this study evaluate reliability handheld ACS-430,...

A field experiment was conducted from 1986 to 1988 on a highly erodible soil in north Mississippi study the effects of seven cotton (Gossypium hirsutum L.) cropping systems erosion, stand establishment, fruiting, earliness, and yield. Stand counts for no-till following hairy vetch (Vicia villosa Roth) averaged 30% less than conventional tillage cotton. No significant difference yield between occurred 1986. Yields 1987 decreased as intensity increased, but this trend reversed 1988. Rainfall...

Maximizing utilization of effluent nutrients by forage grasses requires a better understanding irrigation rate and timing effects. This study was conducted in 1998 1999 on Vaiden silty clay (very-fine, smectitic, thermic Aquic Dystrudert) soil to determine the effects swine lagoon bermudagrass [Cynodon dactylon (L.) Pers.] growth, nitrogen (N) phosphorus (P) recovery, postseason profile NO3(-)-N. Treatments consisted at rates 0, 5, 10, 15, 20 ha-cm. Two additional treatments included 2.5...

Two field experiments were conducted to evaluate the effects of comparable rates swine lagoon effluent and commercial fertilizer at different harvest dates on dry matter yield nutritive value bermudagrass ( Cynodon dactylon L.) grown an acid Vaiden silty clay (very fine, montmorillonitic, thermic, Vertic Hapludalf) johnsongrass Sorghum halepense alkaline Okolona (fine, therimic, Typic Chromudert). At each site, a randomized complete block design with factorial arrangement treatments...

Sustainable cotton (Gossypium hirsutum L.) production will require systems that maintain or augment yields without degrading the soil. Our study was undertaken to determine profitability and fertilizer N rate optimization associated with winter cover management in no-tillage cotton. This conducted beginning fall of 1988 continued through 1992 growing season a producer's field on Caledonia loam (fine, loamy, siliceous, thermic, Typic Paleudalfs) soil 0 2% slope. Winter treatments were fallow,...

Core Ideas Fall‐applied poultry litter and legume cover crop equate to more than 100 kg fertilizer N in corn. Without crop, fall‐applied failed result credit. Fertilizer equivalence of legume/rye biculture was variable between –12 a credit 75 ha –1 . crops increased across the 3‐yr study. Nitrogen from manures fertilizers requires careful management maximize efficiency minimize losses. Cover may conserve nutrients manure cycle corn ( Zea mays L.). To quantify benefits winter (CC) (PL),...

Abstract Constant‐rate blanket applications of fertilizer N can result in both an over and under supply relative to crop utilization on a field‐by‐field basis. Variable‐rate (VR) tailored better meet demand improve use efficiency spatially variable soils. The objectives this study were compare the response corn ( Zea mays L.) canopy reflectance derived vegetation indices (VI) varying rates determine relationships between resulting VIs acquired using two different sensing platforms. Four...

Abstract Associative nitrogen (N 2 )‐fixation (ANF) by bacteria in the root‐zone of perennial bioenergy grasses has potential to replace or supplement N fertilizer and support sustainable production biomass, but its application marginal ecosystems requires further evaluation. In this study, we first combined both greenhouse field experiments, explore fixation effects three temperate feedstocks Miscanthus × giganteus (giant miscanthus, Freedom), Panicum virgatum (switchgrass, Alamo),...

ABSTRACT A three-year field experiment was conducted on an alluvial Morganfield silt soil (coarse silty, mixed, non-acid, thermic, Typic Udifluvent) to determine potassium (K) fertilizer rate and placement effects cotton lint yield K levels. The arranged in a randomized complete block design with four replications. An incomplete factorial arrangement of treatments (including 0, 68, 136, 204 kg ha−1 broadcast, 34, 68 banded combination 136 broadcast zero 102 0 broadcast) used. Cotton...

Nitrogen fertilization is a required production practice for cotton ( Gossypium hirsutum L.) with risks arising from under‐ and over‐fertilization. Tissue testing diagnosing N deficiencies in crops can use leaf blades the total concentration, but this has not been rigorously examined cotton. The primary objective of these experiments was to determine leaf‐N concentration uppermost, fully mature blade below which yield loss could be expected. Nitrogen‐rate field were conducted at 12 research...