Using Spatial Analysis of Anr Gene Transcription Rates for Detecting Irregularities of Nitrate Levels in Cherry Tomatoes (Solanum lycopersicum var. cerasiforme) Organic Greenhouses' Soil.

Using spatial analysis of ANR gene transcription rates for detecting irregularities of Nitrate levels in cherry tomatoes (Solanum lycopersicum var. cerasiforme) organic greenhouses’ soil

Amir Mor-Mussery^1,2, Orit Edelbaum¹, Arie Budovsky³ and Jiftah Ben Asher²

¹ The Robert H. Smith Faculty of Agriculture, Food, and Environment, Rehovot(Hebrew University)

² Katif Center for Coastal Deserts R&D Sdot Negev

³ Judea Regional Research and Development Center, Carmel, Israel.

Organic fertilizers differ from the chemical ones by high inconsistency in their mineralization rates in the soil due to their higher variability and presence of complex organic compounds. This intrinsic property of the organic fertilizers occasionally results in formation of distinct 'soil patches' different from one another with regard to the concentrations of soluble nutrients. This feature together with the different nutritional requirements during the crop’s physiological development complicates the designing of appropriate scheme of organic fertilization.  In order to overcome these difficulties, we designed methodology for monitoring the crop soluble nutrients needs at specific physiological stage using molecular indicators. Adjusting this data to specific organic field could be done using spatial analysis tools. For this purpose, we used cherry tomato (Solanum lycopersicumvar. cerasiforme) organic greenhouse in the Netzer Hazani village, Northern Negev, Israel at 2001 and 2002. The examined nutrient was Nitrate due its high importance to cherry tomatoes growth and yield, and the high difference in its concentrations (both fixed and soluble forms) in the soil of organic fields. Using this methodology, we found that the best molecular marker was the transcription rates of the ANR1 gene which fluctuations in expression allowed defining the optimal concentrations of soluble Nitrate for fertilization needs of the plants at the ripening stage (crucial for yield maximization). The spatial tools used for analyzing this data in the specific greenhouse helped in identifying the surpluses and deficits of soluble nitrate in the soil of various patches. This in turn allowed correcting the Nitrate irregularities in a quick and precise manner by adding Nitrate fertilizers to eliminate the deficits, and adding Nitrate suppressors to cut down the surpluses. Overall, such a strategy minimized the expected damage to the yield. Implementing this methodology on other crops and their essential nutrients will enable constructing accurate and profitable fertilization scheme which will decrease damages to the soil and groundwater (due to nutrients leakages, salinization etc.), and enhance soil sustainability.