Semester of Graduation

Fall 2023

Degree

Master of Science (MS)

Department

School of Plants, Environmental, and Soil Sciences

Document Type

Thesis

Abstract

The constant soil cultivation alongside adverse weather in Louisiana has declined soil and water quality in sugarcane fields. Therefore, the integration of an effective conservation program must be assessed to sustain crop production. Best management practices (BMPs) promote soil health and improve water quality while achieving optimal crop development and cost-effective production system. A study was conducted at two different locations to document the benefits of BMPs (sweeping residue, variable N rate, and cover cropping) implemented collectively and individually compared to the standard farmer’s practices (FP) on sugarcane productivity, nutrient cycling, soil and water quality, and economic return . At site 1 (Sugar Research Station), treatments were arranged in a randomized complete block design with three replications, and site 2 was a demonstration trial in Napoleonville consisting of BMPs and FP treatments on a 4.6- and 2.4 hectare blocks , respectively. Cane yield was determined at harvest using a chopper harvester and a weigh wagon with load cells. Quality components were determined from 10 hand-sampled stalks per plot using a SpectraCane® automated near infrared analyzer. Soil samples were analyzed for NH4+ and NO3- content based on KCl extraction procedure followed by flow injection analysis and Mehlich-3 extractable nutrients by inductively coupled plasma optical emission spectrometry. Soil health parameters included β-glucosidase activity, microbial community, soil organic matter content, and soil respiration. Water samples were analyzed for NH4+ and NO3-- N, total P, total suspended solids, total dissolved solids, turbidity, pH, and electrical conductivity. Across sites, cane and sugar yield responded to collective implementation on BMPs mainly improving nutrient cycling. However, individually, planting cover crops limited sugarcane development due to competition. Plots under variable N rate had higher concentrations of NO3- in runoff water than any of the treatments at site 1. At site 2, FP had higher NO3- in runoff water than BMPs but vice-versa for total P. Positive impact was recorded on soil microbial community under BMPs, increasing the abundance of actinomycetes and Gram (-) bacteria. Moreover, soil respiration, soil organic matter, and enzyme activity fluctuated due to management and weather conditions. Integrating BMPs collectively resulted in higher cost production compared to individual BMP implementation. The economic cost and impact on farmer’s income are among the major challenges that limit the adoption of BMPs in crop production.

Date

11-1-2023

Committee Chair

Brenda Tubana

Available for download on Saturday, October 31, 2026

Share

COinS