Effective use of lower mill mud rates

Effective use of lower mill mud rates in the nutrition program

 

Objectives:

  • The use of banded mill mud at lower rates is a new practice with some unknowns (e.g. nutrient availability) which need to be resolved to avoid potential negative financial and environmental consequences.
  • MT. Catherine Cooperative aims to determine if 50 t/ha of mill mud banded on the “grow zone”:
  1.  
    1. Will provide enough phosphorus for the crop cycle
    2. Needs to be incorporated to ensure early P access by plant cane
    3. Will improve runoff water quality in ratoons relative to traditional application. 
  • The work undertaken will improve grower’s nutrition knowledge (including contribution to guidelines for banded mill mud use in the Central district) profitability & environmental credentials.

Project Activities:

  • Proposed farm trials will be conducted on low phosphorus soils (BSES P < 20 mg/kg) because the major selling point of low mud rates (approximately 50 t/ha) is that they will cost effectively cover P needs for most of the crop cycle. Trials will consist of randomised, replicated strips (T1 = 4, T2 & T3 = 3) each at least 0.4 ha in size. In those treatments receiving mud, the balance of nutrients required to meet “six easy steps recommendations” will be applied using Sucrogen Bioethanol Agservices products. Mud will be applied by Mackay Sugar mud contractors. All trials will be continued beyond the life of the SRDC funding.
  • Trial 1: Set up in fallow plant & continued in ratoons - Is phosphorus availability sufficient to meet crop cycle demands? Is incorporation of the mud band necessary to ensure plant crop P demands are met? Treatments (5):  banded mud planted with no P fertiliser; banded mud planted with P fertiliser; banded mud, incorporated and planted with no P fertiliser; banded mud, incorporated and planted with P fertiliser and no mud control fertiliser.
  •  Trial 2: Set up in young ratoons. Is phosphorus availability sufficient to meet crop cycle demands? Treatments (3): banded mud applied on the stool + ratooning fertiliser including P; banded mud applied on the stool+ ratooning fertiliser excluding P and no mud control fertiliser.
  • Trial 3: Set up in young ratoons. Effect on nitrogen and phosphorus levels in runoff water.  Treatments (3): banded mud applied on the stool; mud at 150# t/ha applied conventionally (to interspace) and no mud control fertiliser. Once the balance of ratooning fertiliser is applied an overhead irrigation will occur.  The second irrigation will be via furrow and designed to cause runoff.  Hand sampling of runoff water will occur at the start, mid-way through and towards the end of the irrigation. Water samples will be analysed for total nitrogen and phosphorus.

# Although 150 t/ha of mud will be a “superseded” practice, this treatment must be included to show how water quality has improved with the new practice.

 

Contact Person: John Fox 0408772666