Management of Compost Amendments to Sustainable Sugarcane Under Marginal Quality Irrigation

Redmond, Thomas W. (2017) Management of Compost Amendments to Sustainable Sugarcane Under Marginal Quality Irrigation. [USQ Project]


Due to increasing resource competition and financial constraints, many cane sugar irrigators are utilising increasingly poor quality water to irrigate cane crops. The effects of such applications of water may have detrimental effects on soils and thus crop growth through the action of salinity and clay colloid dispersion. These conditions have typically been managed through the management of cation species and pH through the use of various amendments.

This dissertation examines the data derived from a three year field trial conducted by TPC Ltd. Tanzania, in order to determine the effectiveness of sulphur amendments on soil conditions under poor quality irrigation. From this data, parameters were developed for inclusion in thermodynamic stoichiometry software models, PHREEQC and HYDRUS1D, in order to be able to model the effect of different amendments.

A leaching trial and laboratory analysis was then conducted on four treatments of amended mill mud composts. Mill mud is a by-product of cane sugar mill, and may serve as an inexpensive source of plant nutrition, as well as a source of beneficial chemistry for ameliorating the effects of poor quality irrigation water due to its high calcium concentration. This leaching trial was conducted with the objective of developing parameters for assessing these composts within the PHREEQC and HYDRUS-1D models.

While a complete model was not able to be developed at this time due to insufficient physico-chemical characterisation of the treated composts, a number of important conclusions were able to be made with respect to the general composition of treated mill mud composts for use in the TPC estate given the specific water and soil characteristics from the field trial. These recommendations include the use of gypsum, or a combination of lime and sulphur as compost amendments, as these will lower the pH of the soil, and provide a continual source of calcium for the forming of stable clay aggregates, reducing the likelihood of detrimental particulate dispersion. It may therefore be concluded that there is a great deal of value to be derived from further development of thermodynamic stoichiometry modelling to inform agronomic decision making.

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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Engineering (Honours) (Agricultural Engineering)
Faculty/School / Institute/Centre: No Faculty
Supervisors: Bennett, John
Date Deposited: 09 Sep 2021 03:30
Last Modified: 31 Jan 2023 01:42

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