Comparative Analysis of Lactu ca sativa Growth Using Compost Versus Conventional Soil

Abstract

Conventional agricultural techniques have been degrading American soils nationwide since the beginnings of modern-day agriculture through practices such as soil tilling, using nitrogen synthetic fertilizers, and monocultural systems. These techniques contribute to degrading soil health, mass emissions of carbon dioxide into the atmosphere, and decreased biodiversity. Regenerative agriculture techniques include the utilization of cover crops, compost, no-tillage, the integration of livestock, and crop rotation. The APS Laboratory for Sustainable Agriculture focused on the effectiveness of compost by comparing the growth of lettuce in four different treatments: 100% Compost (100%C), 75% Compost 25% Miracle-Gro (75%C - 25%MG), 50% Compost 50% Miracle-Gro (50%C - 50%MG), and finally, 100% Miracle-Gro (100%MG). The lettuce seeds were kept in a growth tent for fifteen days during their period of germination before being transferred to four 1 × 1 × 0.15 m plots in the Food Forest at Florida Gulf Coast University (FGCU) for the 60-day growth period. The lettuce crops grew to full bloom and were ready for harvest. Sampling events took place every six days in which crop growth data including wet weight (g), dry weight (g), nitrogen (mg/g), chlorophyll concentration (mg/cm 2 ), and leaf area (LA) (cm 2 ) were collected. Statistical analysis was then conducted from the data. Based on the statistical tests conducted at the 5% significance level using R statistical software, soil treatment type was found to be significant (p = 0.0002). Soil treatment type was shown to have significantly impacted wet weight (p < 0.0001), dry weight (p < 0.0001), and leaf area (p = 0.0011), but not nitrogen ( χ 2 [3] = 3.91, p = 0.2717). 100%C and 100%MG of soil treatments produced the most successful lettuce crops. The 100%C soil treatment yielded lettuce crops with the heaviest wet weights and the largest LAs, and the 100% MG soil treatment yielded the heaviest dry weights and the highest nitrogen readings. Results demonstrate the effectiveness and feasibility of using compost as a technique for regenerative agriculture.