Information

Best Management Practices to Minimise Pollutant Transport from Cotton Production Systems

Level 1 General description

Purpose:

The transport mechanisms and fate of cotton pesticides and nutrients were investigated as part of a major R&D program undertaken by the cotton industry.

Methods (brief)

Sediment, nutrient and pesticide movement from rainfall and irrigation runoff were monitored over two seasons at a paddock scale of 30 Ha for the three treatments (detailed below) and an adjacent conventional cotton treatment.

Three management practices were trailed on farms:

  1. wheat-cotton double crop rotation,
  2. polyacrylamide (PAM) application to irrigation water
  3. planting of vegetative filter strips in irrigation channels.

Key findings (brief)

All three techniques were highly effective at reducing soil erosion, nutrient and pesticide movement. Wheat-cotton rotation reduced soil erosion by 70% and endosulfan concentrations by 40%. Three less insecticide sprays were needed for the wheat-cotton rotation crops. PAM applications to irrigation water reduced sediment loads in runoff by 80%. Vegetative strips filtered runoff water entering tail drains and trapped 65-85% of total endosulfan and 67% of chlorpyrifos in the sediment from runoff water.

Table 1 Runoff and soil loss during 1997/98 and 1998/99 seasons on Black Farm, Emerald. Annual water applied (irrigation + rainfall) = 840.5mm conventional, 868.5 wheat-cotton. (Waters, 2001)

Management Practice

Runoff  mm

Soil loss t/ha

Conventional practice

12.11

1.034

Wheat-cotton double crop rotation

14.7

0.5585

Table 2 Runoff and soil loss during 1997/98 and 1998/99 seasons on Deepfield Farm, Emerald. Annual water applied (irrigation + rainfall) = 838 mm conventional, 785 wheat-cotton. (Waters, 2001)

Management Practice

Runoff  mm

Soil loss t/ha

Conventional practice 1997/98

11.63

0.8385

PAM 1997/98

10.05

0.2715

Location

Emerald Irrigation Area Lat 23°29’ S, Long 148°09’ E.

Related studies

Carroll C, Halpin M, Burger P, Bell K, Sallaway MM ,and Yule DF. (1997). The effect of crop type, crop rotation, and tillage practice on runoff and soil loss on a Vertisol in central Queensland. Australian Journal of Soil Research. 35: 925-39.

Darling Farms, Bourke, NSW. Kimber S. NSW Department of Agriculture.

Silburn DM, and Glanville SF. (2002). Management practices for control of runoff losses from cotton furrows under storm rainfall. I. Runoff and sediment on a black Vertosol.  Australian Journal of Soil Research 40:1-20.

Silburn DM, Simpson BW, and Hargreaves PA. (2002). Management practices for control of runoff losses from cotton furrows under storm rainfall. II. Transport of pesticides in runoff. Australian Journal of Soil Research 40:21-44.

Silburn DM, and Hunter HM. (2009). Management practices for control of runoff losses from cotton furrows under storm rainfall. III. Cover and wheel traffic effects on nutrients (N and P) in runoff from a black Vertosol. Australian Journal of Soil Research 47:221-233.

 

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