bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Criterion for Acceptance of Narrow‐Row Culture in Soybean
Authors: Board James E. , Harville Bobby G. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.] yield response to narrow compared with wide rows in the southeastern USA has usually been greater for late than for optimal plantings. Identification of growth responses explaining this pattern could help develop criteria for acceptance of narrow‐row culture. Narrow‐row yield responses result from increased pod number created by greater light interception and crop growth rate between first flowering and seed initiation (R1 to R5). Lack of yield response to greater light interception in narrow rows in optimal plantings may be related to the association between pod number and total dry matter at harvest maturity (R8). Our objectives were to determine if total dry matter at R8 [TDM(R8)] could be used as a criterion for acceptance of narrow‐row culture and to identify the morphological relation between pod number and TDM(R8). Field studies conducted in 1987 through 1990 used optimal and late planting dates, two soybean cultivars, and several row spacing‐plant density combinations. Results indicate a quadratic response of pod number to TDM(R8). Narrow‐row yield responses occurred when light interception (R1 to R5) increased crop growth rate (R1 to R5) to ≤ 15 g m−2 d−1 and increased TDM(R8) to ≤ 800 g m−2. The ratio of pod number to TDM(R8) declined as TDM(R8) approached 800 g m−2, because of a reduced ratio of branch nodes to branch dry matter. In conclusion, narrow‐row yield responses can be expected if TDM(R8) in wide rows is <800 g m−2.
Simulated Hail Damage to Rice: I. Susceptible Growth Stages
Authors: Counce Paul A. , Wells Bobby R. , Norman Richard J. 
Published: July 2010

AbstractHail damage often occurs to rice (Oryza sativa L.) and crop insurance adjusters need guidelines to assess likely yield reductions. Moreover, defoliation and other types of crop damage can also occur from insects and wind and potential yield effects need to be determined for crop management decisions. Field experiments designed to evaluate effects of simulated hail damage were conducted on a Crowley silt loam soil (fine, montmorillonitic, thermic Typic Albaqualfs) near Stuttgart, AR, from 1980 through 1984. Treatments began with attempts to simulate hail damage and were refined over time based on data from earlier studies. Preflood N fertilization treatments were tested to determine whether vegetative defoliation yield reductions could be remedial. Simulated hail damage at vegetative growth stages resulted in highly variable yield responses. In one treatment, however, leaf removal prior to reproductive growth was remedied by additional preflood N. Significant yield reductions were consistently found for simulated hail damage treatments during reproductive stages of growth. The most severe damage resulted from defoliation followed by culm severing; the least damage was caused by culm bending. These experiments established that yield losses from simulated hail damage could be documented for four stages of growth (panicle initiation, booting, heading, and some time during grain‐filling) for three different kinds of damage (leaf removal, culm severing, and culm bending).
Yield and Nitrogen Requirement of No‐Tillage Corn as Influenced by Cultural Practices
Authors: Eckert Donald J. , Martin Victor L. 
Published: July 2010

AbstractNitrogen fertilizer use efficiency in corn (Zea mays L.) production could be improved if farmers adjusted N fertilizer rates for different yield potentials caused by variations in cultural practices. Five studies were conducted in Ohio, three on Hoytville silty clay (fine, illitic, mesic Mollic Ochraqualf) and two on Riddles silt loam (fine‐loamy, mixed, mesic Typic Hapludalf), to assess the effects of planting date, plant population, N rate, and timing of N application on yield of two corn hybrids grown using no‐tillage methods. Increasing plant population increased grain yield in only one of five site‐year comparisons, but did not increase the amount of N required to produce maximum yield. Crop yield potential varied depending on site‐year, with maximum grain yield indicated by response functions ranging from 5.5 to 11.3 Mg ha−1 for early‐planted corn, and 3.0 to 10.1 Mg ha−1 for late‐planted corn. Nitrogen rates needed to achieve maximum yield varied from 0 to 205 kg N ha−1 for early‐planted corn and from 0 to 175 kg N ha−1 for late‐planted corn, depending on site‐year. In most site‐years, late‐planted corn required less N to achieve maximum yield than early‐planted corn. The reduction in N requirement averaged 60 kg N ha−1, and was directly related to the magnitude of the yield reduction associated with delayed planting. Split applications of N generally produced yields equivalent to application of all N at planting. Split application can offer many farmers a way to use lower N rates to compensate for delayed planting.
Conservation‐Tillage Grain Drill for Furrow‐Irrigated Cropping Systems
Authors: Pearson Calvin H. , Hammon Robert W. , Golus Harold M. , Hain James P. 
Published: July 2010

AbstractConservation‐tillage grain drills, used in research and commercial production, have been designed mainly for rainfed conditions. A no‐till grain drill was fabricated at Colorado State University that can be used for both research and commercial plantings in furrow‐irrigated cropping systems. The drill is 4.58 m long, 3.25 m wide, 1.83 m high, and weighs 2200 kg. It has adjustable drive wheels, lift assist wheels, and seed openers to accommodate various furrow row spacings, seed row spacings, and individual seed opener planting depths. The grain drill has the capability to plant alfalfa (Medicago sativa L.), barley (Hordeum vulgare L.), wheat (Triticum aestivum L. emend. Thell.), oat (Avena sativa L.), soybean [Glycine max (L.) Merr.], dry bean (Phaseolus vulgaris L.), and possibly other seeds. The grain drill has performed well in residue conditions as high as 5 Mg ha−1. Most drill adjustments require ≈1 h.
Response of Hybrid and Open‐Pollinated Safflower to Plant Population
Authors: Gonzalez Jose L. , Schneiter Albert A. , Johnson Burton L. , Riveland Neil R. 
Published: July 2010

AbstractFour safflower (Carthamus tinctorius L.) cultivars were evaluated at five plant populations in experiments over 2 yr at three North Dakota locations. Differences in achene yield due to plant population were not significant. Hybrid AGC‐353 produced significantly higher achene yield than the other cultivars. Number of capitula per plant and achenes per capitulum were the yield components most influenced by plant population. Cultivar effects were significant for all yield components. Plant population did not influence achene oil content; however, significant differences among genotypes occurred. Cultivar S‐541 and hybrid AGC‐353 produced significantly higher and lower achene oil percent, respectively, than the other cultivars. The significantly higher hull content of hybrid AGC‐353 compared with the other cultivars caused the low oil content.
Crop Net Carbon Dioxide Exchange Rate and Radiation Use Efficiency in Soybean
Authors: Rochette Philippe , Desjardins Raymond L. , Pattey Elizabeth , Lessard Robert 
Published: July 2010

AbstractPlant growth is directly related to the fraction of the C fixed by photosynthesis that is converted into phytomass. We report here the results of a study aiming at the estimation of the net CO2 exchange rates (CNCER) of a soybean crop over the growing season. Hourly values of CNCER were estimated based on eddy correlation measurements of CO2 fluxes above the canopy, on chamber measurements of CO2 fluxes at the soil surface, and on the assumption that root respiration can be computed as a fraction of plant daily photosynthesis. Mean daytime CNCER varied between 0.70 and 0.83 mg m−2s−1 for a leaf area index (LAI) greater than 1, with a maximum hourly value of 1.48 mg m−2s−1. Absolute mean nighttime CNCER values were usually <20% of daytime values. Hourly CNCER varied nonlinearly with intercepted photosynthetically active radiation (IPAR). The accuracy of the CNCER estimates was evaluated by comparing the radiation use efficiency of the soybean crop calculated using CNCER estimates with radiation use efficiency calculated using phytomass accumulation. Agreement between the two approaches was within 10% for LAI>2, but calculated CNCER overestimated radiation use efficiency based on phytomass accumulation for smaller values of LAI.
Barley, Canola, and Weed Growth with Decreasing Tillage in a Cold, Semiarid Climate
Authors: Arshad M. A. , Gill K. S. , Coy G. R. 
Published: July 2010

AbstractConventional tillage systems are reported to cause soil degradation, yet appropriate conservation tillage practices have not been developed for cold regions of the northern Canadian Prairies. Effects of conventional, reduced, and zero tillage systems (CT, RT, and ZT) on the growth of dryland spring barley (Hordeum vulgare L.), canola (Brassica campestris L.), and weeds were studied on a clay soil (Natriboralf) near Rycroft in northern Alberta. Each crop‐tillage combination was fixed in space from 1989 through 1991. Each season, the CT plots were tilled once in the preceding fall and twice in the spring prior to seeding; the RT plots were tilled once prior to seeding in the spring; the ZT plots received a preseeding glyphosate [N‐(phosphonomethyl)glycine] application in the spring. Crop residue in ZT was spread evenly by harrowing in the spring just prior to seeding. The 1991 available NO3‐N, NH4‐N, and P in soil or total plant N and P were unaffected by tillage, except that NO3‐N was lower under ZT canola. No consistent effect of tillage was detected on total soil moisture, except for lower moisture in the 0‐ to 10‐cm depth under CT in dry periods. As the study progressed, there was a trend of increased weed population response to tillage, relatively greater weed density under ZT, and a shift in species composition. Mean barley total dry matter (TDM) yield was 3.37, 3.09, and 2.93 Mg ha−1 and grain yield was 1.59, 1.41, and 1.35 35 Mg ha−1 under RT, ZT, and CT, respectively. Mean canola TDM yield was 2.92, 2.36, and 2.12 Mg ha−1 and grain yield was 0.84, 0.66, and 0.59 Mg ha−1, under RT, CT, and ZT, respectively. In most cases, however, tillage effects on mean crop yields were nonsignificant (P < 0.05). Overall, RT was considered to be agronomically and environmentally desirable, due to somewhat better crop yield than either CT or ZT systems and two fewer cultivations than CT.
Estimation of Leaf and Stem Area in the Wind Erosion Prediction System (WEPS)
Authors: Retta Amare , Armbrust Dean V. 
Published: July 2010

AbstractA process‐oriented wind erosion prediction system (WEPS) is being developed. Among the processes to be simulated is the influence of biomass cover in dissipating wind energy at the soil surface. The wind speed profile within the canopy is a function of the distribution of leaf and stem areas by height. Relationships are needed to calculate leaf and stem areas and leaf and stem masses for use in area and mass by height distribution functions. Alfalfa (Medicago sativa L.), corn (Zea mays L.), oat (Avena sativa L.), sorghum [Sorghum bicolor (L.) Moench.], soybean [Glycine max (L.) Merr.], and winter wheat (Triticum aestivum L.) were planted in different years, soil types, and management regimes. The objective was to obtain relationships that could be used to simulate leaf and stem area growth. Measurements were made of leaf and stem areas and leaf and stem masses. Linear and nonlinear regressions of leaf dry weight on leaf area and of stem dry weight on stem area were performed. The linear model fit the leaf data for all crops and also fit the stem data for alfalfa, oat, soybean, and winter wheat, with r2 values ranging from 0.83 to 0.99. The stem data of corn and sorghum fit the nonlinear model (with r2 = 0.99 and 0.92, respectively). Regression parameters for stem appear to be less affected by environmental factors (e.g., management, different years, varieties, or soil types) than are the regression parameters for leaf. The linear and nonlinear relationships can be used to estimate leaf and stem area growth from their respective masses.
Yield Performance of Banana Irrigated with Fractions of Class A Pan Evaporation in a Semiarid Environment
Authors: Goenaga Ricardo , Irizarry Heber 
Published: July 2010

AbstractThere is a scarcity of information regarding the optimum water requirement for banana (Musa acuminata Colla, AAA group) grown under semiarid conditions with drip irrigation in the tropics. A 3‐yr study was conducted on a fine‐loamy, mixed, isohyperthermic Cumulic Haplustoll to determine water requirement, yield, and fruit‐quality traits of the plant crop (PC) and two ratoon crops (R1 and R2) of ‘Grande Naine’ banana subjected to five levels of irrigation. The irrigation treatments were based on Class A pan factors that ranged from 0.25 to 1.25 in increments of 0.25. Drip irrigation was supplied three times a week on alternate days. Results showed significant (P ≤ 0.01) irrigation treatment and crop effects for all yield components, fruit length and diameter, days to flower, and days from flowering to harvest. Highest marketable yield (86.3 Mg ha−1) was obtained from the R2 crop with water application according to a pan factor of 1.25. Plant crop and R1 plants irrigated using the same pan factor yielded 45.3 and 70.3 Mg ha−1, respectively. Increasing the pan factor from 0.25 to 1.25 resulted in weight gains of the third‐upper hand of 70% in PC, 90% in R1, and 122% in R2. Irrigation according to increasing pan factors resulted in significant increases on the number of hands per bunch and the length and diameter of fruits in the third‐upper and last hands in the bunch. It was concluded from this investigation that, to attain high yields, banana grown under semiarid conditions should be irrigated with a pan factor of not less than 1.0.
Critical Petiole Nitrate‐Nitrogen for Lint Yield and Enhanced Maturity in Pima Cotton
Authors: Tewolde Haile , Fernandez Carlos J. , Foss D. C. , Unruh Larry G. 
Published: July 2010

AbstractPetiole NO3‐N concentration (PNN) has been recommended as an indicator of midseason N deficiency in upland cotton (Gossypium hirsutum L.). Its use in Pima cotton (G. barbadense L.) management, exspecially when early maturity is the goal, is not well documented. A 3‐yr study evaluated PNN as an indicator of N status in Pima cotton in order to identify a critical minimum PNN level for yield and early maturity. Treatments were five preplant applied N rates of 0 to 180 kg ha−1 in 1990 and 0 to 269 kg ha−1 in 1991 and 1992. The PNN was measured throughout boll development, starting ≈ 2 wk before or at first flower. Applied N significantly (P ≤ 0.05) affected PNN in 1991 and 1992, when residual soil N was low, but not in 1990, when residual N was high; differences among treatments in 1991 and 1992 were largest during early flowering. PNN was a good indicator of plant N status within but not across seasons. Based on early‐flowering samples, the critical PNN level for lint yield was 3.84 g kg−1 in 1991 and only 1.75 g kg−1 in 1992; in 1990, residual soil N alone resulted in PNN much higher than the critical levels in the other years. PNN < 2 g kg−1 in 1991 and < 1 g kg−1 in 1992 resulted in earlier maturity, but also resulted in less lint yield. Pima cotton PNN did not exceed an average of 11 g kg−1, in contrast to 24 to 30 g kg−1 reported for upland cotton. Plant growth or petiole anatomical variables that cause year‐to‐year variation in PNN should be identified and the necessary normalization made before PNN can be used as a midseason diagnostic tool in Pima cotton.
Measured and Simulated Surface Soil Drying
Authors: Durar Abdu A. , Steiner Jean L. , Evett Steven R. , Skidmore Edward L. 
Published: July 2010

AbstractThe USDA initiated the Wind Erosion Prediction System (WEPS) to develop improved technology for predicting wind erosion. A HYDROLOGY submodel has been developed for WEPS to simulate the soil energy and water balances. This study was conducted to evaluate the performance of the HYDROLOGY submodel in predicting surface soil drying. Water content was measured gravimetrically in a bare 5‐ by 30‐m plot for 14 d after irrigation during July and August 1991. The plot was located 5 m directly north of a bare weighing lysimeter at the USDA‐ARS Conservation and Production Research Laboratory at Bushland, TX. Hourly samples were taken from depth increments of 0 to 2, 2 to 6, 6 to 10, 10 to 30, and 30 to 50 mm. Furthermore, soil cores were taken to 900 mm at 6‐h intervals. Water content was also measured daily at the lysimeter and between the lysimeter and gravimetric sampling plot using a neutron probe to 2.1 m. The submodel accurately predicted that no deep percolation occurred throughout the simulation period. Simulation results agreed well with the measured daily evaporation rates from the lysimeter (r2 = 0.96). Furthermore, the submodel reasonably estimated the soil water content profiles, particularly the status of soil water at the soil‐atmosphere interface. The mean absolute error, which describes the average absolute deviation between measured and simulated soil water contents, was 0.015 m3 m−3. The HYDROLOGY submodel of WEPS shows a potential to accurately simulate soil water dynamics, as needed for wind erosion modeling. The submodel successfully predicts the changes in water content at the soil surface, which relate to the susceptibility of the soil to wind erosion.
Nitrogen and Phosphorus Uptake in Pearl Millet and Its Relation to Nutrient and Transpiration Efficiency
Authors: Payne William A. , Hossner Lloyd R. , Onken Arthur B. , Wendt Charles W. 
Published: July 2010

AbstractDepending on soil and rainfall characteristics, pearl millet [Pennisetum glaucum (L.) R. Br.] production in the Sahel can be limited by inefficient use of nutrients, especially N and P, or by inefficient use of water. This study measured pearl millet N and P uptake and compared the efficiency with which N, P, and water are used for growth under varied soil P and water availability. Millet was grown outdoors in semiarid West Texas using rain‐sheltered pots of low pH, P‐deficient sandy soil. Treatments consisted of four P levels (0–56 g−2) and two water treatments (stressed and not). Plant P concentration decreased strongly with plant age; added P and water stress increased stem and leaf P concentration. Plant N concentration also decreased with age and increased with water stress, but decreased with added P. Because of the effects of age, water availability, and P level on organ nutrient concentration, P‐use efficiency (PUE) increased with age, decreased with water stress, and decreased with added P. Nitrogen‐use efficiency (NUE) also increased with age and decreased with water stress, but tended to increase with added P. Shoot transpiration efficiency (WUET) increased with water stress and added P, and so varied inversely with PUE throughout the growth cycle. Phosphate root uptake efficiency (PRE) was less sensitive than PUE to age, P availability, and water stress, because of the compensating effect of root growth; PRE was also positively correlated with WUET and yield. For crop improvement programs interested in increasing both P‐ and water‐use efficiency, PRE is probably a better selection index than PUE.
Dry Bean Responses to Nitrogen Fertilizer in Two Tillage and Residue Management Systems
Authors: Liebman Matt , Corson Sue , Rowe Richard J. , Halteman William A. 
Published: July 2010

AbstractFew data currently exist concerning dry bean (Phaseolus vulgaris L.) production systems in which minimum tillage techniques and cover crops are integrated with reduced reliance on chemical inputs. For this reason, we conducted a 2‐yr field experiment in central Maine to compare bean growth, N status, and seed yield in two tillage and residue management systems: conventional planting into a tilled seedbed and two herbicide applications vs. no‐tillage planting into a rye (Secale cereale L.) cover crop and a single herbicide application. Nitrogen fertilizer was applied at 0, 45, 90, and 135 kg N ha−1 to both systems. In 1990, a year characterized by wet early‐season conditions, bean seed yield was 26% lower in the no‐tillage‐rye mulch system than the conventional system, and increased linearly with N fertilizer rate in both systems. In contrast, in 1991, when early‐season rainfall was near normal, yield of the no‐tillage‐rye mulch system was 23% lower than that of the conventional system without N fertilizer, but increased quadratically to equal yield of the conventional system when N was applied. In both years, seed yield was significantly correlated with early and midseason leaf N concentration and late‐season leaf area index. Weed growth was greater in the no‐tillage‐rye mulch system than the conventional system in 1990, but equally low in both systems in 1991, when an additional cultivation was performed. Because the no‐tillage‐rye mulch system we examined may reduce bean growth, N status, and yield, we recommend that other management strategies be pursued. Use of legume green manures as N sources in temperate bean production systems merits attention.
Grain Yield and Weed Biomass of a Wheat–Lentil Intercrop
Authors: Carr Patrick M. , Gardner John J. , Schatz Blaine G. , Zwinger Steven W. , Guldan Steven J. 
Published: July 2010

AbstractIntercropping cereal with pulse crops often increases total grain production in subtropical regions. Our objective was to determine if a yield advantage resulted when lentil (Lens culinaris Medik.) was intercropped with wheat (Triticum aestivum L. emend. Theil.) in a cool semiarid region. A field experiment was conducted during 1989, 1990, and 1991 under dryland management in south central North Dakota. Lentil and hard red spring wheat were each sown alone and intercropped in different planting patterns and populations. Plants were hand clipped at the soil surface and threshed to provide grain yield estimates in all 3 yr. In 1991, grain was also harvested with a research combine to assess if intercrops could be harvested mechanically. Grain yield of wheat was unaffected by intercropping (P < 0.05). Intercropping reduced grain yield of lentil by 87 to 95% when yield estimates were based on samples harvested manually, and by 70 to 85% when samples were harvested mechanically. The increased height at which pods formed on intercropped compared with sole‐cropped lentil plants and subsequent enhancement in mechanical harvestability of grain in intercrops partially explains this difference in yield estimates between harvesting methods. The land equivalent ratio was 1.15 for grain yield across intercrop treatments with mechanical harvest, and 1.03 for the intercrop treatments when grain was harvested manually. While harvestability of the short‐statured lentil was enhanced in this investigation by intercropping, the low lentil yield under intercropping suggests that wheat‐lentil mixtures are probably not adapted to cool semiarid regions.