Document Type : Research Article

Authors

1 Shahrekord University

2 College of Agriculture, ShahreKord University

Abstract

Introduction: Ammonium (NH4+) and nitrate (NO3-) ions are the two main forms of nitrogen (N) for plants. But, they influence differently on growth and chemical composition of plants. The effect of N form on plant growth depends on plant species, development stage of plant, pH, and temperature, ratio of NH4+ /NO3- and nitrogen level of nutrient solution. Lettuce is one of the leafy vegetables that has been cultivated in soilless culture in many greenhouses in the world. This plant can respond well to NH4+ nutrition, but the information about optimum NH4+/NO3- ratio in the nutrient solution and respond of lettuce cultivars to partial replacement of NO3- by NH4+ is scarce. Application of nitrification inhibitors such as 3, 4-dimethylpyrazole phosphate (DMPP) with ammonium fertilizers lead to high N-use efficiency as well as reducing denitrification and leaching losses. Nitrification inhibitors are compounds that delay the biological oxidation of ammonium to nitrite by depressing the activity of Nitrosomonas bacteria. This study was conducted to elucidate the effect of nitrogen form (N-NO3− and N-NH4+) and the use of a nitrification inhibitor (DMPP) on chemical composition and yield of lettuce (Lactuca sativa L.) cultivars in research greenhouse of Shahrekord University.
Materials and Methods: A factorial experiment using completely randomized design was carried out with two factors of NH4+/NO3- ratio (0:100, 15:85 with and without DMPP, 30:70 with and without DMPP) and lettuce cultivars (Teresa and California) with three replications under hydroponic conditions. Lettuce plants were grown in 1.7 L plastic pots (one plant per pot) and the substrate used was mixture of cocopeat + perlite with ratio of 2:1 (v/v). Different nutrient solutions were applied by hand two or three times per week to obtain a leaching fraction of 5 to 20%. After seven weeks plants were harvested, fresh weight of shoots and roots were determined and plants were dried in an oven at 60 °C. Then, dry weight of shoots and roots were measured and plants were ground for nutrient analysis including of P, K, Ca, Mg, Fe, Mn, Zn and Cu.   
Results and Discussion: The results showed that application of nutrient solution with NH4+/NO3- ratio of 30:70 in California cultivar and 15:85 in Teresa cultivar led to significant increase shoot P concentration compared with the 0:100 of NH4+/NO3- ratio (40 and 13%, respectively). This was due to synergistic effect of NH4+ on the uptake of P by roots. In both Teresa and California cultivars, replacing 30% NO3- in the nutrient solution with NH4+ resulted to significant decrease shoot K concentration (27.3 and 14.8% in Teresa and California cultivars, respectively) as well as shoot Ca concentration (42.0 and 31.1% in Teresa and California cultivars, respectively) compared with the 0:100 of NH4+/NO3- ratio. This decrease is related to antagonistic effects of NH4+ on the uptake of K and Mg by roots. In Teresa cultivar, increasing the NH4+/NO3- ratio to 15:85 led to the meaningful increase of shoot Fe (97%), Mn (68%) and Zn (54%) concentration in comparison with 0:100 of NH4+/NO3- ratio. But, in California cultivar shoot Mn concentration increased (65%) with 30% replacement of NO3- by NH4+. This means that changing NH4+/NO3- ratio in the nutrient solution is an excellent approach to control the relative uptake of cations and anions by the plant. The greatest quantity of shoot fresh weight in Teresa (334 g pot-1) and California (435 g pot-1) cultivars were obtained from 0:100 and 15:85 of NH4+/NO3- ratios, respectively. The current study indicates that the lettuce cultivars respond differently to the form of N supply. There is a genotypic variability in the ability of plants to supply carbon skeletons for NH4+ assimilation in the roots. Thus, California cultivar is a genotype sensitive to enhanced ammonium nutrition and Teresa cultivar is a genotype insensitive to enhanced ammonium nutrition. Increasing the NH4+/NO3- ratio to 30:70 led to the meaningful decrease (42%) of root fresh weight in comparison with nutrient solution without NH4+. Application of nitrification inhibitor DMPP with the NH4+/NO3- ratios of 15:85 and 30:70 had not significant effect on the shoot fresh and dry weight as well as the concentration of P, K and Cu in the shoot of both lettuce cultivars in comparison to these ratios without DMPP.
Conclusion: The results suggest that the NH4+/NO3- ratios of 0:100 and 15:85 can be recommended for production of Teresa and California lettuce cultivars under the conditions of the present study, respectively.

Keywords

1- Abd-Elmoniem E.M., Abou-Hadid A.F., El-Shinawy M.Z., El-Beltagy A.S., and Eissa A.M. 1996. Effect of nitrogen form on lettuce plant grown in hydroponic system. Acta Horticulture 434: 47-52.
2- Ali Ehyayi M., and Behbehanizadeh A.A. 1993. Methods of Soil Analysis. Soil and Water Research Institute Press, Tehran.
3- Arzani A. 2007. Commercial and Home Hydroponics. Isfahan University of Technology Press, Isfahan.
4- Bagheri M.H., and Roosta H.R. 2013. Effect of nitrogen form and oxygen levels in nutrient solution on growth and some macronutrients in hydroponically grown lettuce (Lactuca sativa cv. Great leak). Journal of Horticultural Science 27: 148-157. (In Persian with English abstract)
5- Behbahani Motlaq F., Rabii V., Taheri M., Vaezi A., and Khademi R. 2012. Effect of ammonium: nitrate ratio on growth and nitrogen uptake and potassium: sodium ratio in two olive varieties in saline conditions. Seed and Plant Production 28: 313-329. (In Persian with English abstract)
6- Beritto D.T., and Kronzucker H.J. 2002. NH4+ toxicity in higher plants. Journal of Plant Physiology, 159:567-584.
7- Chen W., Luo J.K., and Shen Q.R. 2005. Effect of NH4+-N/NO3--N ratios on growth and some physiological parameters of Chinese cabbages cultivars. Pedosphere 15: 310-318.
8- Clark M.B., Mills H.A., Robacker C.D., and Latimer J.G. 2003. Influence of nitrate: ammonium ratios on growth and elemental concentration in two azalea cultivars. Journal of Plant Nutrition 26: 2503-2520.
9- Dekreij C., Voogt W., and Baas R. 2003. Nutrient solutions and water quality for soilless cultures. Research Station for Floriculture and Greenhouse Vegetables. Report, No. 196.
10- Emami A. 1996. Methods of Plant Analysis. Soil and Water Research Institute Press, Tehran.
11- Errebhi M., and Wilcox G.E. 1990. Plant species response to ammonium-nitrate concentration ratios. Journal of Plant Nutrition 13: 1017-1029.
12- Heberer J.A., and Below F.E. 1989. Mixed nitrogen nutrition and productivity of wheat grown in hydroponics. Annals of Botany 63: 643-649.
13- Helali S.M., Nebli H., Kaddour R., Mahmoundi H., Lachaal M., and Ouerghi Z. 2010. Influence of nitrate-ammonium on growth and nutrition of Arabidopsis thaliana. Plant and Soil 336: 65-74.
14- Kafkafi U. 1990. Root temperature, concentration and the ratio NO3/NH4 effect on the plant development. Journal of Plant Nutrition 13: 1291-1306.
15- Kane C.D., Jasoni R.L., Peffley E.P., Thompson L.D., Green C.J., Pare P., and Tissue D. 2006. Nutrient solution and solution pH influences on onion growth and mineral content. Journal of Plant Nutrition 29: 375-390.
16- Kiani Sh., Malakouti M.J., Tabatabaei S.J., and Kafi M. 2009. Influence of different NH4+/NO3- ratios and calcium levels on growth, nutrients concentration and quality of rose flower. Iranian Journal of Soil Research 23: 23-33. (In Persian with English abstract)
17- Kotsiras A., Olympios C.M., Drosopoulos J., and Passam H.C. 2002. Effect of nitrogen form and concentration on the distribution of ions within cucumber fruit. Journal of American Society for Horticultural Science 95: 175-183.
18- Levander O.A. 1990. Fruit and vegetable contributions to dietary mineral intake in human health and disease. HortScience 25: 1486-1488.
19- Mahlangu R.I.S., Maboko M.M., Sivakumar D., Soundy P., and Jifon J. 2016. Lettuce (Lactuca sativa L.) growth, yield and quality response to nitrogen fertilization in a non-circulating hydroponic system. Journal of Plant Nutrition 39: 1766-1775.
20- Marschner P. 2012. Mineral Nutrition of Higher Plants. Academic Press, London.
21- Najafi N., Parsazadeh M., Tabatabaei S.J., and Oustan Sh. 2010. Effects of nitrogen form and pH of nutrient solution on the uptake and concentrations of potassium, calcium, magnesium and sodium in root and shoot of spinach plant. Water and Soil Science 20: 111-131. (In Persian with English abstract)
22- Pasda G., Hahndel R., and Zerulla W. 2001. Effect of fertilizers with the new nitrification inhibitor DMPP (3, 4-dimethylpyrazole phosphate) on yield and quality of agricultural and horticultural crops. Biology and Fertility of Soils 34: 85-97.
23- Ramos L., Bettin A., Herrada B.M.P., Arenas T.L., and Becker S.J. 2013. Effects of nitrogen form and application rates on the growth of petunia and nitrogen content in the substrate. Communications in Soil Science and Plant Analysis 44: 473-479.
24- Roosta H.R. 2010. The comparison of ammonium or nitrate-grown lettuce and spinach in a hydroponic system. Journal of Science and Technology of Greenhouse Culture 1: 57-64. (In Persian with English abstract)
25- Roosta H.R., and Schjoerring J.K. 2008. Root carbon enrichment alleviates ammonium toxicity in cucumber plants. Journal of Plant Nutrition 31: 941-958.
26- Rothstein D.E., and Cregg B.M. 2005. Effects of nitrogen form on nutrient uptake and physiology of Fraser fir (Abies fraseri). Forest Ecology and Management 219: 69-80.
27- Savvas D., Passam H.C., Olympios C., Nasi E., Moustaka E., Mantzos N., and Barouchas P. 2006. Effects of ammonium nitrogen on lettuce grown on pumice in a closed hydroponic system. Journal of Horticultural Science 41: 1667-1673.
28- Schortemeyer M., Stamp P., and Feil B. 1997. Ammonium tolerance and carbohydrate status in maize cultivars. Annals of Botany 79: 25-30.
29- Serna M.D., Borras R., Legaz F., and Millo E. P. 1992. The influence of nitrogen concentration and ammonium/nitrate ratio on N-uptake, mineral composition and yield of citrus. Plant and Soil 147: 13-23.
30- Tabatabaei S.J., Fatemi L., and Fallahi E. 2006. Effect of ammonium: nitrate ratio on yield, calcium concentration, and photosynthesis rate in strawberry. Journal of Plant Nutrition 29: 1273-1285.
31- Wang B., and Shen Q.R. 2011. NH4+-N/NO3--N ratios on growth and NO3--N remobilization in root vacuoles and cytoplasm of lettuce genotypes. Canadian Journal of Plant Science 91: 411-417.
32- Wang X., and Below F.E. 1992. Root growth, nitrogen uptake, and tillering of wheat induced by mixed-nitrogen source. Crop Science 32: 997-1002.
33- Wang X.T., and Below F.E. 1998. Accumulation and partitioning of mineral nutrients in wheat as influenced by nitrogen form. Journal of Plant Nutrition 21: 49-61.
34- Wen X., Ikeda H., and Oda M. 2000. The absorption, translocation, and assimilation of urea nitrate or ammonium in tomato plant at different plant growth stages in hydroponic culture. Scientia Horticulturae 84: 275-283.
35- Woodson W.R., and Boodley J.W. 1982. Effects of nitrogen form and potassium concentration on growth, flowering and nitrogen utilization of greenhouse roses. Journal of American Society for Horticultural Science 107: 275-278.
36- Zerulla W., Barth T., Dressel J., Von Locquenghien K.E.K.H., Pasda G., Radle M., and Wissemeier A.H. 2001. 3, 4- Dimethylpyrazole phosphate (DMPP) - a new nitrification inhibitor for agriculture and horticulture. Biology and Fertility of Soils 34: 79-84.
CAPTCHA Image