Organic Fertilizers for Greenhouse:Productivity and Microbiology

Abstract

Organic fertilizer regimens consisting of combinations of composts (yard waste, manure, or spent mushroom substrate) and liquid fertilizers (fish- or plant-based) evaluated against conventional hydroponic fertilizers in two experiments with tomatoes grown in peat-based substrate. Crop yield and fruit quality were and several assays of substrate microbial activity and community profiles (fluorescein diacetate analysis and EcoLog, values, nematode counts) were conducted. grown in 20% to 40% compost (yard waste or yard waste plus swine manure) plus continuously applied liquid source of organic potassium (K), calcium (Ca), magnesium (Mg), and sulphate (SO4) could not be sustained more than 1 month before nutrient became visible. Supplementation with a nitrogen (N)- and phosphorus (P)- plant-based liquid fertilizer at the point when plant deficiencies became subsequently produced yields'80% that of the hydroponic control. In a second , the proportion of mushroom or yard waste compost was increased to 50% of ix, and liquid delivery of K, Ca, Mg and SO4 plus either plant-based or fish-based Nand containing liquid feeds was started at the date of transplanting. In this case, yields equal to that of the hydroponic control (8.5 kg/plant) were observed in treatments. The most productive organic treatment was the mushroom compost with a low concentration of the plant-based liquid fertilizer. In general, tomatoes had a lower postharvest decay index (better shelf life) than did the controls, possibly as an indirect consequence of overall reduced yield in those . High concentrations of both organic liquid feeds resulted in lower yields as a of treatment-induced fusarium crown and root rot. In contrast to some previous , those treatments showing fusarium crown and root rot also had the highest gross activity. Measures of gross microbial activity and numbers of microbivorous were higher (average of 37% and 6.7 times, respectively) in compost/organic treatments than in the hydroponic control. Community physiological profile of the populations, on the other hand, did not differ between organic and hydroponic . Nematode populations were significantly correlated with gross microbial activity in the organic treatments.