scholarly journals Phosphorus Fertilizer Calibration Studies with Three Mustard Cabbage Varieties in Tropical Soils with Initial High P Levels

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1107D-1107
Author(s):  
Hector Valenzuela ◽  
Ted Goo ◽  
Dave Wall ◽  
Roger Corrales ◽  
Susan Migita ◽  
...  
Keyword(s):  
Field Experiments ◽  
Tropical Soils ◽  
Vegetable Production ◽  
Double Row ◽  
Application Rates ◽  
P Fertilizer ◽  
P Rate ◽  
Agricultural Areas ◽  
The University ◽  
High Elevations

Regulatory agencies are concerned about the high levels of P fertilizers used in some agricultural areas because of potential runoff to aquatic habitats. Farmers in Hawaii traditionally make blanket P applications even in soils high in P. Many farmers, especially those growing leafy crops, claim to observe responses to P, especially during the cooler winter months. A series of 15 field experiments were conducted over a 2-year period to evaluate the response of three mustard cabbage varieties to five P fertilizer rates across three locations in the state, and across several planting seasons. All experiments were conducted in soils with P levels that the University of Hawaii determined to be high in P. The experimental design for each experiment consisted of three commercial mustard cabbage varieties, and five P application rates (from 0 to 400 kg·ha-1 of TSP). Each plot consisted of a 3-m double-row, with plants spaced 15 cm within the row, and 30 cm between rows, with four replications per treatment. Each experiment thus consisted of 60 plots (three varietie × five P rate × four replications). After the initial P applications were made on each site, three consecutive crops were planted on the same site without making any additional P applications. Data collected included soil fertility prior to initiation and after experiment completion, tissue nutrient levels, plant height during crop establishment, and individual head weight of 20 plants per treatment. Our data show that even in soils with initial high levels of P, mustard cabbage responded to P applications, especially at high elevations and during the cooler months of the year. From this data we recommend that the University recalibrate its P fertilizer recommendations for leafy vegetable production in Hawaii.

scholarly journals Effect of Gypsum Application Rate, Soil Type, and Soil Calcium on Yield, Grade and Seed Quality of Runner Type Peanut Cultivars

2017 ◽  
Vol 44 (1) ◽  
pp. 13-18 ◽  
Author(s):  
J.A. Arnold III ◽  
J.P. Beasley ◽  
G.H. Harris ◽  
T.L. Grey ◽  
M. Cabrera
Keyword(s):  
Field Experiments ◽  
Seed Quality ◽  
Soil Depth ◽  
Application Rate ◽  
Seed Vigor ◽  
Application Rates ◽  
Peanut Cultivars ◽  
Research And Education ◽  
The University ◽  
Gypsum Application

ABSTRACT Calcium (Ca) availability in the 0 to 8 cm soil depth often limits peanut yield and influences grade in the southeastern United States. Field experiments were conducted in 2012 and 2013 at the University of Georgia's Coastal Plain Experiment Station, Tifton, GA (CPES) and the Southwest Georgia Research and Education Center, Plains, GA (SWREC) to determine large-seeded (Georgia-06G) and medium-seed sized (Georgia Greener) runner-type cultivar response to gypsum application rates of 0, 560, 1120, 1650 kg/ha. Peanut pod yield and grade (TSMK) were significantly different between locations with 7610 and 6540 kg/ha at CPES and SWREC, respectively. However, there were no differences between peanut cultivars or gypsum rates. Standard germination, seed vigor (cold germination), and seed Ca content analysis were also conducted on subsamples from each plot. Average peanut seed germination was 97% across all samples. No differences were observed for standard germination or vigor testing. Differences in locations were observed for yield, TSMK, percent jumbo, percent medium kernels, and seed Ca content. Peanut cultivar and gypsum application rate had effects on seed Ca concentration. Seed Ca concentration levels were 825 and 787 mg/kg for Georgia Greener and Georgia-06G, respectively. Seed Ca content increased as field gypsum application rate increased at both locations.

scholarly journals Crisphead Lettuce Cultivar Response to Fertilizer Phosphorus

1992 ◽  
Vol 117 (5) ◽  
pp. 721-724 ◽  
Author(s):  
R.T. Nagata ◽  
C.A. Sanchez ◽  
F.J. Coale
Keyword(s):  
Total Mass ◽  
Field Experiments ◽  
P Uptake ◽  
Yield Response ◽  
Marketable Yield ◽  
Fertilizer Recommendations ◽  
P Fertilizer ◽  
P Rate ◽  
Growing Conditions ◽  
The One

Four field experiments were conducted during 1988 to 1990 to evaluate the response to fertilizer P of six crisphead lettuce (Latuca sativa L.) cultivars grown on Histosols. There were season × cultivar interactions for total mass produced, marketable yield, and P uptake by lettuce. A significant yield response to fertilizer P was demonstrated during all four seasons. The performance of individual cultivars within a given season led to cultivar × P rate interactions for marketable yield. However, there were no significant P rate × cultivar interactions for total mass produced, P uptake, and marketable yield during the one season when growing conditions were near ideal. Calculated critical soil-test P values for both eastern and western lettuce types produced in Florida were all within error currently associated with P fertilizer recommendations for lettuce produced in Florida. Therefore, we conclude that no immediate change in P fertilizer recommendations is required for the new western-type lettuce cultivars produced on Histosols in Florida.

scholarly journals 651 PB 025 FERTILIZER BANDING REDUCES P INPUTS INTO COMMERCIAL LETTUCE PRODUCTION ON HISTOSOLS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 526a-526
Author(s):  
N. M. El-Hout
Keyword(s):  
Field Experiments ◽  
Soil Test ◽  
Band Placement ◽  
Pooled Data ◽  
P Fertilizer ◽  
P Rate ◽  
Soil Test P ◽  
Large Production ◽  
Use Efficiency ◽  
Environmentally Sensitive

Band placement has been recognized as an effective strategy for improving P fertilizer-use efficiency on Histosols, which are often characterized as environmentally sensitive wetlands, and for reducing P loading of drainage waters from these soils. Recent studies indicate that crisphead lettuce (Lacruca sativa L.) yields can be optimized with a band-P rate one-third of that required with broadcast applications. However, such findings have not been verified in large production plots. Five field experiments were conducted between 1991 and 1993 to evaluate the response of crisphead lettuce produced commercially on Histosols to band P rates. Liquid P fertilizers were placed in lo-cm-wide strips, 8.5-cm below the seed at planting in rates ranging from 0 to 224 kg P ha-1. Lettuce yields increased significantly with P rate in all experiments. Irrespective of initial soil-test-P index, lettuce yields within each experiment were maximized with a band rate 54% of that required in a broadcast. The pooled data for all experiments showed a similar trend. These findings provided a means of making alternative band fertilizer recommendations by utilizing an existing preplant broadcast soil test.

scholarly journals Banding P to Improve Fertilizer Use Efficiency of Lettuce

1990 ◽  
Vol 115 (4) ◽  
pp. 581-584 ◽  
Author(s):  
C.A. Sanchez ◽  
S. Swanson ◽  
P.S. Porter
Keyword(s):  
Field Experiments ◽  
Root Zone ◽  
Critical Concentration ◽  
Leaf Tissue ◽  
Tissue Analysis ◽  
Lettuce Seeds ◽  
P Fertilizer ◽  
P Rate ◽  
Use Efficiency ◽  
Leaf P

Five field experiments were conducted from 1986 to 1989 to compare broadcast and band P fertilization of crisphead lettuce (Lactuca sativa L.) on Histosols. Rates of P were 0, 50, 100, 200, and 300 kg P/ha applied broadcast or banded. Broadcast P was surface-applied and disked into the soil 1 day before bedding and planting. Banded P was placed in strips 8 cm wide, 5 cm below the lettuce seeds at planting. Lettuce yields were significantly(P < 0.01) increased by P rate in all experiments. However, significant rate-by -placement interactions indicated that response of lettuce to P varied by placement. Lettuce yields were generally optimized with a band P rate one-third of that required with broadcast placement. Analysis of soil samples collected in the lettuce bed after fertilization indicated that banded P increased available P in the lettuce root zone compared to broadcast fertilization. Lettuce leaf P concentration increased with P rate and generally was greater when P was banded. The critical concentration of P in lettuce leaf tissue at the six- to eight-leaf stage was 0.37%. Banding P fertilizer did not reduce the availability of other essential nutrients, as indicated by tissue analysis.

AMOUNT AND STRUCTURE OF THE BIOLOGICAL FERTILITY OF SOYA, DEPENDING ON THE SYSTEM OF MAIN TILLAGE OF SOIL AND MEASURES TO OPTIMIZE NUTRITION MODE

2020 ◽  
Author(s):  
M. Novokhatskyi ◽  
◽  
V. Targonya ◽  
T. Babinets ◽  
O. Gorodetskyi ◽  
...  
Keyword(s):  
Field Experiments ◽  
Optimal Number ◽  
Soil Tillage ◽  
Forest Steppe ◽  
Biological Productivity ◽  
Tillage Systems ◽  
Application Rates ◽  
Tillage System ◽  
Biological Yield ◽  
The Impact

Aim. Assessment of the impact of the most common systems of basic tillage and biological methods of optimization of nutrition regimes on the realization of the potential of grain productivity of soybean in the Forest-Steppe of Ukraine. Methods. The research used general scientific (hypothesis, experiment, observation) and special (field experiment, morphological analysis) methods Results. The analysis of the results of field experiments shows that the conservation system of soil cultivation, which provided the formation of 27.6 c/ha of grain, is preferable by the level of biological yield of soybean. The use of other systems caused a decrease in the biological yield level: up to 26.4 c/ha for the use of the traditional system, up to 25.3 c/ha for the use of mulching and up to 23.0 c/ha for the use of the mini-till. With the use of Groundfix, the average biological yield of soybean grain increases to 25.6 c / ha for application rates of 5 l/ha, and to 28.2 c/ha for application rates of 10 l/ha when control variants (without the use of the specified preparation) an average of 22.6 c/ha of grain was formed with fluctuations in soil tillage systems from 21.0 (mini-bodies) to 25.8 c/ha (traditional).The application of Groundfix (10 l/ha) reduced the seed abortion rate from 11.0% (average without biofertilizer variants) to 8.0%, forming the optimal number of stem nodes with beans, increasing the attachment height of the lower beans and improving other indicators of biological productivity soybeans. Conclusions. It has been found that the use of the canning tillage system generates an average of 27.6 cent soybean grains, which is the highest indicator among the main tillage systems within the scheme of our research. The use of Groundfix caused a change in this indicator: if the variants with a conservative system of basic tillage without the use of biological preparation (control) were formed on average 24.1 c/ha, the use of Ground Licks caused the increase of biological productivity up to 29.4 c/ha, and at a dose of 10 l/ha biological yield was 32.2 c/ha. It was found that both the use of Groundfix and the basic tillage system influenced the elements of the yield structure: the density of the plants at the time of harvest depended more on the tillage system than on the use of Groundfix; the use of Groundfix and increasing its dose within the scheme of our studies positively reflected on the density of standing plants; the height of attachment of the lower beans and reduced the abortion of the seeds.

Drip Irrigation and Stand Establishment Affect Yield and Quality of Cantaloupe

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 545d-545
Author(s):  
D.I. Leskovar ◽  
J.C. Ward ◽  
R.W. Sprague ◽  
A. Meiri
Keyword(s):  
Field Experiments ◽  
Irrigation System ◽  
Fruit Size ◽  
Growth Yield ◽  
Vegetable Production ◽  
Silty Clay ◽  
Dry Land ◽  
Stand Establishment ◽  
Yield And Quality

Water pumping restrictions of high-quality irrigation water from underground aquifers is affecting vegetable production in Southwest Texas. There is a need to develop efficient deficit-irrigation strategies to minimize irrigation inputs and maintain crop profitability. Our objective was to determine how growth, yield, and quality of cantaloupe (Cucumis melo L. cv. `Caravelle') are affected by irrigation systems with varying input levels, including drip depth position and polyethylene mulch. Stand establishment systems used were containerized transplants and direct seeding. Field experiments were conducted on a Uvalde silty clay loam soil. Marketable yields increased in the order of pre-irrigation followed by: dry-land conditions, furrow/no-mulch, furrow/mulch, drip-surface (0 cm depth)/mulch, drip-subsurface (10-cm depth)/mulch, and drip-subsurface (30 cm depth)/mulch. Pooled across all drip depth treatments, plants on drip had higher water use efficiency than plants on furrow/no-mulch or furrow/mulch systems. Transplants with drip-surface produced 75% higher total and fruit size No. 9 yields than drip-subsurface (10- or 30-cm depth) during the first harvest, but total yields were unaffected by drip tape position. About similar trends were measured in a subsequent study except for a significant irrigation system (stand establishment interaction for yield. Total yields were highest for transplants on drip-subsurface (10-cm depth) and direct seeded plants on drip-subsurface (10 and 30 cm depth) with mulch.

scholarly journals Genotypic Variation in Nutrient Uptake Requirements of Rice Using the QUEFTS Model

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Tao Sun ◽  
Xin Yang ◽  
Sheng Tang ◽  
Kefeng Han ◽  
Ping He ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Field Experiments ◽  
Hybrid Rice ◽  
Genotypic Variation ◽  
Tropical Soils ◽  
Study Data ◽  
Japonica Rice ◽  
Rice Varieties ◽  
Indica Hybrid Rice ◽  
Validation Experiments

Nutrient requirements for single-season rice using the quantitative evaluation of the fertility of tropical soils (QUEFTS) model in China have been estimated in a previous study, which involved all the rice varieties; however, it is unclear whether a similar result can be obtained for different rice varieties. In this study, data were collected from field experiments conducted from 2016 to 2019 in Zhejiang Province, China. The dataset was separated into two parts: japonica/indica hybrid rice and japonica rice. To produce 1000 kg of grain, 13.5 kg N, 3.6 kg P, and 20.4 kg K were required in the above-ground plant dry matter for japonica/indica hybrid rice, and the corresponding internal efficiencies (IEs) were 74.0 kg grain per kg N, 279.1 kg grain per kg P, and 49.1 kg grain per kg K. For japonica rice, 17.6 kg N, 4.1 kg P, and 23.0 kg K were required to produce 1000 kg of grain, and the corresponding IEs were 56.8 kg grain per kg N, 244.6 kg grain per kg P, and 43.5 kg grain per kg K. Field validation experiments indicated that the QUEFTS model could be used to estimate nutrient uptake of different rice varieties. We suggest that variety should be taken into consideration when estimating nutrient uptake for rice using the QUEFTS model, which would improve this model.

Lateral coefficient of friction for characterizing winter road conditions

2016 ◽  
Vol 43 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Sahar Salimi ◽  
Somayeh Nassiri ◽  
Alireza Bayat ◽  
Don Halliday
Keyword(s):  
Field Experiments ◽  
Surface Friction ◽  
Concrete Surface ◽  
Snow Accumulation ◽  
Frictional Heat ◽  
Vehicle Speed ◽  
Test Road ◽  
Winter Road ◽  
Friction Measurements ◽  
The University

Real Time Traction Tool (RT3)-Curve was used in this study to evaluate the effect of ice and snow on tire–road lateral friction coefficient, herein referred to as the Halliday Friction Number (HFN). The field experiments for the study were performed in winter 2012–2013 on the University of Alberta’s test road facility in Edmonton, Alberta. Each run was repeated at three target speeds under varied road conditions, bare dry, dry with ice patches, ice, and three levels of snow accumulation. No considerable correlation was found between vehicle speed and the friction measurements for bare dry, ice- and snow-covered conditions. Expectedly, the bare dry asphalt concrete surface had the highest HFN, the presence of ice reduced the dry surface friction by 55%. The accumulation of snow on the dry surface reduced the HFN further than ice, by 69, 75, and 81% for light, moderate, and heavy snow, respectively. A falling trend was observed for friction as more snow accumulated on the ground. Analysis of the effect of number of truck passes over ice at −3.5 and −5 °C showed that ice can become more slippery after each pass of traffic. A similar analysis for snow revealed that more passes over moderate snow will compact the fresh snow into a slippery surface. For light snow, even at low temperatures (<−10 °C), passes of traffic will melt the snow through frictional heat and result in higher friction values.

Weed Management in Southeastern Peanut (Arachis hypogaea) with AC 263,222

1996 ◽  
Vol 10 (1) ◽  
pp. 145-152 ◽  
Author(s):  
John S. Richburg ◽  
John W. Wilcut ◽  
Daniel L. Colvin ◽  
Gerald R. Wiley
Keyword(s):  
Weed Control ◽  
Arachis Hypogaea ◽  
Weed Management ◽  
Field Experiments ◽  
Common Ragweed ◽  
Yellow Nutsedge ◽  
Application Rates ◽  
Ac 263,222

Field experiments conducted at four locations in Georgia and two locations in Florida during 1992 and 1993 evaluated AC 263,222 application rates and timings, systems, and mixtures for weed control, peanut injury, and yield. All rates of AC 263,222 applied early POST (EPOST) or POST controlledIpomoeamorningglories and smallflower morningglory at least 90%, and purple and yellow nutsedge at least 81%. Florida beggarweed and sicklepod control generally was highest when metolachlor was applied PPI followed by AC 263,222 applied EPOST at 71 g/ha, AC 263,222 at 27 or 36 g/ha plus bentazon plus paraquat applied POST, or with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Acifluorfen and acifluorfen plus bentazon reduced Florida beggarweed and sicklepod control at several locations when applied in mixture with AC 263,222. Common ragweed and hairy indigo control were 85 to 95% with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Highest peanut yields were obtained with treatments providing high levels of weed control.

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