Runoff, soil loss, and nutrient transport from cropping systems on Red Ferrosols in tropical northern Australia

Abstract

Runoff, soil loss, and nutrient loss were assessed on a Red Ferrosol in tropical Australia over 3 years. The experiment was conducted using bounded, 100-m2 field plots cropped to peanuts, maize, or grass. A bare plot, without cover or crop, was also instigated as an extreme treatment. Results showed the importance of cover in reducing runoff, soil loss, and nutrient loss from these soils. Runoff ranged from 13% of incident rainfall for the conventional cultivation to 29% under bare conditions during the highest rainfall year, and was well correlated with event rainfall and rainfall energy. Soil loss ranged from 30 t/ha.year under bare conditions to <6 t/ha.year under cropping. Nutrient losses of 35 kg N and 35 kg P/ha.year under bare conditions and 17 kg N and 11 kg P/ha.year under cropping were measured. Soil carbon analyses showed a relationship with treatment runoff, suggesting that soil properties influenced the rainfall runoff response. The cropping systems model PERFECT was calibrated using runoff, soil loss, and soil water data. Runoff and soil loss showed good agreement with observed data in the calibration, and soil water and yield had reasonable agreement. Long-term runs using historical weather data showed the episodic nature of runoff and soil loss events in this region and emphasise the need to manage land using protective measures such as conservation cropping practices. Farmers involved in related, action-learning activities wished to incorporate conservation cropping findings into their systems but also needed clear production benefits to hasten practice change.

Evaluation of rice wild relatives as a source of traits for adaptation to iron toxicity and enhanced grain quality

“…Nevertheless, extremely low LBS of some RWR, especially O. meridionalis accessions (Fig 1a) indicate that specific RWR do possess adaptive genes which can supplement the gene pool for adaptive rice breeding. The high level of adaptation of this particular species may have an evolutionary background as it is often found at the edges of freshwater lagoons, temporary pools and swamps of the Northern territories of Australia [41], where Fe rich soils such as Ferrosols occur [42]. As a member of the O. sativa complex with an AA genome, O. meridionalis represents an easily accessible gene pool, and crosses with O. sativa have previously been reported [31].…”

A pragmatic parameterisation and calibration approach to model hydrology and water quality of agricultural landscapes and catchments

“…This section describes the HowLeaky model's performance across a wide range of environments and management scenarios using daily observed data and applying a pragmatic and manual calibration approach described above. Some sites were evaluated using coarser model outputs from published studies (Waters 2009;Tullberg et al 2001;Cogle et al, 2011).…”

“…Observed and estimated runoff, sediment and total phosphorus loss in runoff from small plots at the Kairi Research Station (Cogle et al, 2011) over 3 years for four soil management conditions: bare soil; cropping aggressive tillage, cropping with reduced tillage; and pasture are shown in Table 5.…”

Reversing land degradation through grasses: a systematic meta-analysis in the Indian tropics

“…Raising and maintenance of perennial grasses on degraded soils has been suggested as a means to improve soil quality and sequester carbon in the soil. Several studies have shown that the inclusion of grasses in the agricultural landscape often improves the productivity of system while providing opportunities to create carbon (C) sinks (Ghosh et al, 2009;Cogle et al, 2011;Huang et al, 2010;Mutegi et al, 2008). Soils typically account for 70-90 % of the total carbon sequestered in a grassland ecosystem (Batjes, 2001).…”