Abstract

PATERLINI, Hernán; GONZALEZ, María Virginia  and  PICONE, Liliana Inés. Lettuce production in a soil with application of poultry litter compost. Cienc. suelo [online]. 2019, vol.37, n.1, pp.38-50. ISSN 1850-2067.

In the horticultural belt in General Pueyrredón is common to apply 30 to 60 t ha^-1 of poultry litter, being lettuce one of the main crops in which it is applied. The objective of this study was to evaluate the effects of composted poultry litter application on production parameters of red lettuce, as well as on certain edaphic properties. The treatments were: T0 (without compost), T15 (15 t ha^-1 of compost dry base) and T30 (30 t ha^-1 of compost dry base). During the development of crop, leave number per plant and plant height were recorded, and finally yield was measured. Soil pH, electrical conductivity (EC), extractable P-Bray 1 and total carbon (TC) were determined in the first 20 cm, and nitrate (N-NO3) in depth intervals of 0-20, 20-40 and 40-60 cm. At the end of crop cycle, there were no differences in the average number of leaves per plant, the average height of stems and the yield between T15 and T30 but they significantly exceeded T0. Number of leaves and height of plants showed an exponential growth, and a significant and high correlation (p <0.05, r = 0.99). Soil pH was not affected by application of compost despite its high pH (8.2), indicating the buffer capacity of soil. The CT was also not affected by compost although it tended to increase with dose, with values of 26.8, 28.6 and 29.6 g kg^-1 for T0, T15 and T30, respectively in the first cm. The EC was significantly higher in T30 (0.60dS m^-1) than in T0 (0.34dS m^-1) without affecting yield. There was no difference in NO3-N concentration among treatments for 20-40 and 40-60cm depth intervals while it was lower in T0 than in T30 for the 0-20 cm layer. Extractable P reached levels of 151.91 mg P kg in T30. Nutrients supplied by the composted poultry litter N, P, Ca, Mg and K, in both doses, far exceeded the nutritional requirements of lettuce. The use efficiency of compost as N and P source was very low, 14 ^-19% and 6 - 8% of N as nitrate and P extractable, respectively.

Keywords : Lactuca sativa L.; organic fertilizers; nitrogen; phosphorus.