Florida ranks first in the production of tomato in the United States [U.S. Department of Agriculture (USDA), 2011] and uses ≈30,000 acres for production (USDA, 2018). Tomato production systems involve intensive management of nutrients and water on typically sandy textured soils. Optimizing applications of nutrient and water and their use efficiencies is, therefore, important for minimizing potential losses of nutrients to the environment, particularly nitrogen (N), in sandy soils. Synthetic N fertilizer is a relatively low-cost input resulting in potential excessive applications. This ultimately leads to leaching of N into groundwater through nitrate-nitrogen (NO3-N) pollution (Paltineanu et al., 1980) and degrades surface water bodies through eutrophication (Carpenter et al., 1998). In most agricultural soils, NO3-N is the dominant N form available for crop accumulation (Mengel and Kirkby, 2001), where agricultural sandy soils can intensify NO3-N leaching.
Nitrogen is a common limiting factor for tomato production in the southeastern United States (Everett, 1976; Locascio et al., 1997; Rhoads et al., 1996), resulting in significant N use. In Florida, the recommended rate of N fertilization for tomato production is 200 lb/acre (Mylavarapu et al., 2017a), although commercial growers may apply more than double this amount (357–500 lb/acre) (Everett, 1976; Rhoads et al., 1996). With increases in the use of N fertilizer occurring, it is critical to produce information on fertilizer accumulation by the crop to improve production practices that can increase efficiency and decrease N fertilizer loss.
Nitrogen use efficiency (NUE) of agricultural systems is estimated at 50% (Smil, 1999), where unused N fertilizer may remain in the soil or be subject to denitrification, volatilization, and leaching to groundwater (Carpenter et al., 1998). Nitrogen use efficiency is defined as the N accumulation by plants divided by the amount of N fertilizer applied. Increasing NUE in agricultural production systems is of critical importance because the consumption and demand for N fertilizer will continue to grow as populations increase (Xu et al., 2012). In 2008, about 162 million tonnes of N, phosphorous (P), and potassium (K) fertilizer was used and has increased to 200 million tonnes of fertilizer in 2018 [Food and Agriculture Organization of the United Nations (FAO), 2015]. Of this 200 million tonnes, 119 million tonnes came from N alone (FAO, 2015). Currently, researchers and government agencies are attempting to look at optimizing NUE in agricultural production while minimizing negative impacts to the environment. For example, the Florida Department of Agriculture and Consumer Services (FDACS) implemented best management practices (BMPs) to reduce nutrient loading from agricultural production into bodies of water (FDACS, 2015). Efforts have included the improvement and implementation of soil test recommendations and other cultural practices to improve NUE of agricultural systems and reduce leaching (Way, 2007). For tomato production on sandy soils in Florida, BMPs include drip irrigation, splitting N fertilizer applications (13 weekly applications), and mulched beds, all of which help improve the NUE.
In addition to improving fertilizer N efficiency in tomato production systems, the agronomic apparent recovery of N fertilizer (APR) will be studied. The agronomic calculation of APR is defined as the difference in N accumulation (pounds per acre) between plots receiving fertilizer and unfertilized plots, and it is in proportion to the amount of N fertilizer applied. The APR index evaluates the ability of the crop to absorb soil N, where decreases in APR occur when N supply exceeds crop N demand (Greenwood and Hunt, 1986). A decline in APR, therefore, typically occurs when N fertilizer rates are increased. An APR value of zero would indicate that N accumulation of the unfertilized crops did not differ from those that were fertilized with N fertilizer. In other words, the plant likely took up native soil N primarily. On the other hand, an APR value of 100% indicates that N accumulation of the crop was higher than what was applied as N fertilizer (Craswell and Godwin, 1984; Mengel et al., 2006). Therefore, determining APR in vegetable production systems is important to ascertain the efficiency of applied N fertilizer to a system that may or may not provide sufficient native soil N to the crop.
Information on NUE and APR could aid in providing additional information on determining the efficiency of current management practices related to rate and timing of N fertilizer applications (Zemenchik and Albrecht, 2002). Limited information is available where NUE and APR are compared and evaluated together (Zemenchik and Albrecht, 2002), especially in the case of evaluating the efficiency of N fertilizer application on vegetable production systems. Therefore, a study was conducted on determining the efficiency of applied N fertilizer on tomato produced on sandy soils, using NUE and APR as indices of evaluating efficiency. Thus, our objectives were to determine the effect of N fertilization rate on the responses of tomato, including 1) N accumulation in plant tissues, 2) crop N requirement, and 3) apparent recovery and efficiency of N.
Adams, S.R., Cockshull, K.E. & Cave, C.R.J. 2001 Effect of temperature on the growth and development of tomato fruits Ann. Bot. 88 869 877
Anderson, P.C., Rhoads, F.M., Olson, S.M. & Hill, K.D. 1999 Carbon and nitrogen budgets in spring and fall tomato crops HortScience 34 648 652
Carpenter, S.R., Caraco, N.F., Correll, D.L., Howarth, R.W., Sharpley, A.N. & Smith, V.H. 1998 Nonpoint pollution of surface waters with phosphorus and nitrogen Ecol. Appl. 8 559 568
Craswell, E.T. & Godwin, D.C. 1984 The efficiencies of nitrogen fertilizer applied to cereals in different climates Adv. Plant Nutr. 1 1 55
Everett, P.H. 1976 Effect of nitrogen and potassium on fruit yield and size of mulch-grown staked tomatoes Proc. Florida State Hort. Soc. 89 159 162
Fixen, P., Brentrup, F., Bruulsema, T.W., Garcia, F., Norton, R. & Zingore, S. 2015 Nutrient/fertilizer use efficiency: Measurement, current situation and trends, p. 8–38. In: Managing water and fertilizer for sustainable agricultural intensification. 11 Nov. 2019. <http://www.iwmi.cgiar.org/Publications/Books/PDF/managing_water_and_fertilizer_for_sustainable_agricultural_intensification.pdf>
Florida Department of Agriculture and Consumer Services (FDACS) 2015 Water quality/quantity best management practices for Florida vegetable and agronomic crops. 10 Jan. 2020. <https://www.fdacs.gov/content/download/77230/file/vegAgCropBMP-loRes.pdf>
Food and Agriculture Organization of the United Nations (FAO). 2015 World fertilizer trends and outlook to 2018. 16 Feb. 2018. <http://www.fao.org/3/a-i4324e.pdf>
Greenwood, D.J. & Hunt, J. 1986 Effect of nitrogen fertilizer on the nitrate contents of field vegetables grown in Britain J. Sci. Food Agr. 37 373 383
Heuvelink, E. 2005 Tomatoes. CABI Publ., Cambridge, MA
Hochmuth, G. & Cordasco, K. 2000 A summary of N, P, and K research with tomato in Florida. Vegetable Nutrition Management Series. Hort. Sci. Dept., Florida Coop. Ext. Serv., Inst. Food Agr. Sci., Univ. Florida, Gainesville
Hochmuth, G. & Hanlon, E. 2014 A summary of N, P, and K research with tomato in Florida. Univ. Florida, Inst. Food Agr. Sci. SL355. 20 Nov. 2018. <http://edis.ifas.ufl.edu/cv236>
Jansson, S.L. & Persson, J. 1982 Mineralization and immobilization of soil nitrogen, p. 229–248. In: F.J. Stevenson (ed.). Nitrogen in agricultural soils. Amer. Soc. Agron., Madison WI
Kadiyala, M.D.M., Mylavarapu, R.S., Li, Y.C., Reddy, G.B., Reddy, K.R. & Reddy, M.D. 2014 Uptake efficiency of 15N-urea in flooded and aerobic rice fields under semi-arid conditions Paddy Water Environ. 13 545 556
Locascio, S.J., Hochmuth, G.J., Rhoads, F.M., Olson, S.M., Smajstrla, A.G. & Hanlon, E.A. 1997 Nitrogen and potassium application scheduling effects on drip-irrigated tomato yield and leaf tissue analysis HortScience 32 230 235
Masclaux-Daubresse, C., Daniel-Vedele, F., Dechorgnat, J., Chardon, F., Gaufichon, L. & Suzuki, A. 2010 Nitrogen uptake, assimilation and remobilization in plants: Challenges for sustainable and productive agriculture Ann. Bot. 105 1141 1157
Mengel, K. & Kirkby, E.A. 2001 Nitrogen. Principles of plant nutrition. Kluwer Academic Publ., Dordrecht, The Netherlands
Mengel, K., Hutsch, B. & Kane, Y. 2006 Nitrogen fertilizer application rates on cereal crops according to available mineral and organic soil nitrogen Eur. J. Agron. 24 343 348
Mylavarapu, R., Hochmuth, G. & Liu, G. 2017a UF/IFAS standardized nutrient recommendations for vegetable crop production in Florida. Soil Water Sci., IFAS Coop. Ext. Serv., Univ. Florida CIR1152
Mylavarapu, R.S., d’Angelo, W., Wilkinson, N. & Moon, D. 2017b UF/IFAS extension soil testing laboratory (ESTL) analytical procedures and training manual. Soil Water Sci., IFAS Coop. Ext. Serv., Univ. Florida Circ. 1248
Paltineanu, I.C., Hera, C., Paltineanu, R., Idriceunu, A., Eliade, G., Suteu, G., Bologa, M., Canarache, A., Postolache, T. & Apostol, I. 1980 Irrigation water and N fertilizer application efficiencies for reduction of water and N losses and for water pollution control, p. 169–193. In: Proc. Soil Nitrogen as Fertilizer or Pollutant Res. Coordination Mtg., Piracicaba, Brazil, 3–7 July 1978, Intl. Atomic Energy Agency, Vienna, Austria
Rhoads, F.M., Olson, S.M., Hochmuth, G.J. & Hanlon, E.A. 1996 Yield and petiole-sap nitrate levels of tomato with N rates applied preplant or fertigated Proc. Soil Crop Sci. Soc. Fla. 55 20 22
Sato, S., Peet, M.M. & Thomas, J.F. 2000 Physiological factors limit fruit set of tomato (Lycopersicon esculentum Mill.) under chronic, mild heat stress Plant Cell Environ. 23 719 726
Syers, J.K., Johnston, A.E. & Curtin, D. 2008 Efficiency of soil and fertilizer phosphorus use, reconciling changing concepts of soil phosphorus behavior with agronomic information. FAO Fert. Plant Nutr. Bul. 18. 14 Nov. 2019. <http://www.fao.org/3/a-a1595e.pdf>
U.S. Department of Agriculture 2011 Florida agriculture by the numbers. 14 Nov. 2019. <https://www.nass.usda.gov/Statistics_by_State/Florida/Publications/Annual_Statistical_Bulletin/FL_Agriculture_Book/2011/2011%20FL%20Ag%20by%20the%20Numbers.pdf>
U.S. Department of Agriculture 2017 Web soil survey. 13 Jan. 2018. <http://websoilsurvey.sc.egov.usda.gov>
U.S. Department of Agriculture 2018 Vegetables 2017 summary. 14 Nov. 2019. <https://downloads.usda.library.cornell.edu/usda-esmis/files/02870v86p/5425kd81z/9019s517t/VegeSumm-02-13-2018.pdf>
Way, P.L. 2007 Development of a functional, widely accepted and adopted BMP program in response to government regulation Amer. J. Potato Res. 84 39 46
Zemenchik, R.A. & Albrecht, K.A. 2002 Nitrogen use efficiency and apparent nitrogen recovery of Kentucky bluegrass, smooth bromegrass, and orchardgrass Agron. J. 94 421 428
Zotarelli, L., Scholberg, J.M., Dukes, M.D. & Muñoz-Carpena, R. 2007 Monitoring of nitrate leaching in sandy soils: Comparison of three methods J. Environ. Qual. 36 953 962
Zotarelli, L., Scholberg, J.M., Dukes, M.D., Muñoz-Carpena, R. & Icerman, J. 2009a Tomato yield, biomass accumulation, root distribution and irrigation water use efficiency on a sandy soil, as affected by nitrogen rate and irrigation scheduling Agr. Water Manage. 96 23 34
Zotarelli, L., Dukes, M.D., Scholberg, J.M., Muñoz-Carpena, R. & Icerman, J. 2009b Tomato nitrogen accumulation and fertilizer use efficiency on sandy soil, as affected by nitrogen rate and irrigation scheduling Agr. Water Manage. 96 1247 1258
Zuraiqi, S., Qawasmi, W., Deek, I. & Mohammad, M.J. 2002 Management of nitrogen fertigation of tomato with the use of 15N technology. Joint FAO/Intl. Atomic Energy Agency Div. Nuclear Techniques in Food Agr., Vienna, Austria