EFFICIENCY OF SOIL AND TEZONTLE IN PRODUCTION SYSTEMS OF TOMATO UNDER GREENHOUSE

Abstract

In México, 80% of the greenhouse area is cultivated under soil conditions and in the remaining some type of inert substrate is used. In this study we determined the commercial yield, water and nutrient use efficiency of tomato (Lycopersicon esculentum Mill. cv. ‘Gironda’) grown in two substrates, soil and tezontle. Commercial yield under soil conditions was 34.1 kg m^-2, with a total nutrient supply of 920, 342, 1520, 1050 y 290 kg ha^-1 of N, P₂O₅, K₂O, Ca y Mg, respectively, and a nutrient use efficiency of 2.7, 1.0, 4.5, 3.1 y 0.9 kg t^-1 of commercial fruit for those nutrients, in a soil not previously used for horticulture. Total water supply was 801 L m^-2, with a water use efficiency (WUE) of 43 kg of fruit m^-3 of water. Commercial yields of tomato in the tezontle treatments were statistically equal whit an average of 31.4 kg m^-2, and an average nutrient supply of 1748, 452, 3636, 2170 y 731 kg ha^-1 of N, P₂O₅, K₂O, Ca y Mg respectively, and an average nutrient use efficiency of 5.6, 1.4, 11.6, 6.9 y 2.3 kg t^-1 of fruit. Loses of nutrients in the drainage of the tezontle treatments averaged 56, 6, 42, 48 y 60 % respectively, with a total water supply of 1114 L m^-2, a drainage of 36 % and an WUE of 28.2 kg m^-3. These results show the potential of soil for saving water and nutrients, since the productivity in both systems was the same.