Yield and Quality of Carrot Cultivars with Eight Nitrogen Rates and Best Management Practices

Carrot (Daucus carota) production has increased in North Florida and South Georgia since 2015. Deep sandy soils, moderate winter climate, availability of irrigation water, and proximity to eastern markets are favorable for carrot production in the region. Nitrogen (N) is required for successful carrot production, and the current recommended N application rate in Florida is 196 kg·ha−1. The objective of this study was to verify the recommended N rate for the sandy soils of North Florida using current industry standard cultivars and practices. Carrot cultivars for the whole carrot fresh market, Choctaw and Maverick, and cultivars for the cut-and-peel market, Triton and Uppercut 25, were direct seeded on 102-cm-wide pressed bed tops on 29 Oct. 2016 and 2 Nov. 2017 in Live Oak, FL. Eight N application rates (56, 112, 168, 224, 280, 336, 392, and 448 kg·ha−1) were tested, and all N applications were placed on the bed top. N rates were split and timed to increase N use efficiency. Regression analyses were used to determine the optimal N rate for carrots in North Florida. A quadratic plateau regression for both seasons combined indicated 206 kg·ha−1 N was the optimal rate for carrots, with marketable yield of 71.3 Mg·ha−1, regardless of cultivar. All four cultivars attained acceptable yield including Uppercut 25, which exhibited significant foliage damage following freezing temperatures. This study resulted in updated information on best management practices for carrot production in Florida, especially nutrient stewardship.

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Tomato Growth, Yield, and Root Development, Soil Nitrogen and Water Distribution as Affected by Nitrogen and Irrigation Rates on a Florida Sandy Soil

HortScience ◽

10.21273/hortsci15177-20 ◽

2020 ◽

Vol 55 (11) ◽

pp. 1744-1755

Author(s):

Ibukun T. Ayankojo ◽

Kelly T. Morgan ◽

Davie M. Kadyampakeni ◽

Guodong D. Liu

Keyword(s):

Open Field ◽

Management Practices ◽

Irrigation Management ◽

Growth Yield ◽

Fresh Market ◽

Marketable Yield ◽

N Application ◽

Tomato Production ◽

Application Rates ◽

N Rates

Effective nutrient and irrigation management practices are critical for optimum growth and yield in open-field fresh-market tomato production. Although nutrient and irrigation management practices have been well-studied for tomato production in Florida, more studies of the current highly efficient production systems would be considered essential. Therefore, a two-season (Fall 2016 and Spring 2017) study was conducted in Immokalee, FL, to evaluate the effects of the nitrogen (N) rates under different irrigation regimes and to determine the optimum N requirement for open-field fresh-market tomato production. To evaluate productivity, the study investigated the effects of N rates and irrigation regimes on plant and root growth, yield, and production efficiency of fresh-market tomato. The study demonstrated that deficit irrigation (DI) targeting 66% daily evapotranspiration (ET) replacement significantly increased tomato root growth compared with full irrigation (FI) at 100% ET. Similarly, DI application increased tomato growth early in the season compared with FI. Therefore, irrigation applications may be adjusted downward from FI, especially early during a wet season, thereby potentially improving irrigation water use efficiency (iWUE) and reducing leaching potential of Florida sandy soils. However, total marketable yield significantly increased under FI compared with DI. This suggests that although DI may increase early plant growth, the application of DI throughout the season may result in yield reduction. Although N application rates had no significant effects on biomass production, tomato marketable yield with an application rate of 134 kg·ha−1 N was significantly lower compared with other N application rates (179, 224, and 269 kg·ha−1). It was also observed that there were no significant yield benefits with N application rates higher than 179 kg·ha−1. During the fall, iWUE was higher under DI (33.57 kg·m−3) than under FI (25.57 kg·m−3); however, iWUE was similar for both irrigation treatments during spring (FI = 14.04 kg·m−3; DI = 15.29 kg·m−3). The N recovery (REC-N) rate was highest with 134 kg·ha−1 N; however, REC-N was similar with 179, 224, and 269 kg·ha−1 N rates during both fall and spring. Therefore, these study results could suggest that DI could be beneficial to tomato production only when applied during early growth stages, but not throughout the growing season. Both yield and efficiency results indicated that the optimum N requirement for open-field fresh-market tomato production in Florida may not exceed 179 kg·ha−1 N.

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Optimizing nitrogen fertilizer use for more grain and less pollution

10.21203/rs.3.rs-361734/v1 ◽

2021 ◽

Author(s):

Keyu Ren ◽

Minggang Xu ◽

Rong Li ◽

Lei Zheng ◽

Shaogui Liu ◽

...

Keyword(s):

Crop Production ◽

Management Practices ◽

Application Rate ◽

N Fertilizer ◽

N Application ◽

Fertilizer Use ◽

Application Rates ◽

Operational Practices ◽

N Management ◽

N Fertilizer Use

Abstract Optimal nitrogen (N) management is critical for efficient crop production and agricultural pollution control. However, it is difficult to implement advanced management practices on smallholder farms due to a lack of knowledge and technology. Here, using 35,502 on-farm fertilization experiments, we demonstrated that smallholders in China could produce more grain with less N fertilizer use through optimizing N application rate. The yields of wheat, maize and rice were shown to increase between 10% and 19% while N application rates were reduced by 15–19%. These changes resulted in an increase in N use efficiency (NUE) by 32–46% and a reduction in N surplus by 40% without actually changing farmers’ operational practices. By reducing N application rates in line with official recommendations would not only save fertilizer cost while increasing crop yield, but at the same time reduce environmental N pollution in China. However, making progress towards further optimizing N fertilizer use to produce more grain with less pollution would require managements to improve farmers’ practices which was estimated to cost about 11.8 billion US dollars to implement.

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Nitrogen Fertilization Guidelines for Bare-Ground and Plastic Mulch Cabbage Production in Florida

EDIS ◽

10.32473/edis-hs1428-2021 ◽

2021 ◽

Vol 2021 (6) ◽

Author(s):

Lincoln Zotarelli ◽

Charles Barrett ◽

Andre Luiz B. R. Da Silva ◽

Christian Christensen ◽

Gary England

Keyword(s):

Nitrogen Fertilizer ◽

Best Management Practices ◽

Nitrogen Fertilization ◽

Management Practices ◽

Management Strategies ◽

Nitrogen Losses ◽

Bare Ground ◽

Plastic Mulch ◽

Fresh Market ◽

Best Management

This new 9-page publication of the UF/IFAS Horticultural Sciences Department focuses on the nitrogen fertilizer best management practices (BMP) for green fresh-market and processing cabbage head production in Florida. This publication aims to provide management strategies that comply with statewide BMP guidelines to optimize economic yield while minimizing nitrogen losses to the environment. Written by L. Zotarelli, C. E. Barrett, A. L. B. R. da Silva, C. T. Christensen, and G. K. England.https://edis.ifas.ufl.edu/hs1428

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Nitrogen and water requirements of fertigated cabbage in Ontario

Canadian Journal of Plant Science ◽

10.4141/cjps09028 ◽

2010 ◽

Vol 90 (1) ◽

pp. 101-109 ◽

Cited By ~ 12

Author(s):

A W McKeown ◽

S M Westerveld ◽

C J Bakker

Keyword(s):

Brassica Oleracea ◽

Best Management Practices ◽

Management Practices ◽

Nutrient Management ◽

Sandy Loam ◽

Field Capacity ◽

Dry Weight ◽

Research Station ◽

Marketable Yield ◽

N Application

Increasing nutrient and water regulations have necessitated development of best management practices for application of nitrogen (N) and water. This study was conducted to determine if there was an optimal balance of N and water applied for late storage cabbage (Brassica oleracea L. var. capitata). Five rates of N and five irrigation rates arranged in a response surface design replicated three times were supplied to Huron cabbage grown on sandy loam soil to study the interaction of N and water applied. Plots were located at the University of Guelph, Simcoe Research Station, Ontario, Canada from 2003 to 2005. Total and marketable yields were maximized from a low of 278 kg ha-1 N in 2005 to above the highest rate tested (400 kg ha-1 N) in the other 2 yr. In 2005, there were 29 d above 30 °C and marketable yield was 49% lower than 2004, which had only 1 d above 30 °C. A target soil water value of 100% of field capacity was required to maximize yield in all 3 yr. More N is required as the water supply increases. The main influence of irrigation and N application was on head volume. Head density based on fresh weight was not influenced by irrigation or N application, but head density based on dry weight decreased with increased N application. Irrigation and N application should be managed concurrently to maximize yield and quality and N and irrigation efficiency for late storage cabbage. However, N and water will not prevent lost yield due to hot days, which suggests that late-cabbage yields are very sensitive to high air temperatures. Key words: Brassica oleracea var. capitata, cabbage, irrigation, fertigation, quality, nutrient management, air temperature

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