Ground Cover Supplement : GC Supplement - Mixed farming
GROUND COVER MIXED FARMING 12 SUITABLE LAND USE FOR LAND TYPE Pest-suppressive landscapes Environments that favour the movement of beneficial insects into crops could help in the fight against invertebrate pests By Nancy Schellhorn DEEDI's Dr Jamie Hopkinson, who leads the Queensland component of the field work, with one of the interception traps being used on the Darling Downs to quantify the movement of beneficial insects between native vegetation and crops. PHOTO: CSIRO Grain & Graze 2 projects on SUITABLE LAND USE FOR LAND TYPE Region Project title East South Australia Understanding soil types to optimise land use Northern Risk analysis of farming practices on different land types Northern Matching farming practices to land capability Northern Victoria Making the most of irrigation for meat and grain production Western Australia Using 'rules of thumb' at the break of the season to decide what to grow (and graze) and where (on-farm) For regional Grain & Graze 2 (G&G2) contacts see the back cover been established to try to understand the features that may create landscapes that are less prone to pests. Fieldwork is being conducted in the three GRDC regions, with two 10-kilometre-diameter landscapes being studied in each. One landscape mostly contains grain crops and only limited non- crop habitats, which can include stock routes, unimproved pasture and regrowth areas. The other is a more complex landscape containing a variety of crops and substantial areas of non-crop habitats. Previous work has shown that a 10km-diameter habitat is appropriate for such studies. The fieldwork consists of three major components: (i) identifying habitats where pests and natural enemies breed, (ii) assessing their movement between crops and native vegetation, and (iii) determining their relative time of arrival to the crop. The latter is important as the best pest control happens when natural enemies arrive about the same time as the pests. Since February 2010, monthly surveys have been conducted in crops and native remnant habitat in the six landscapes across the three regions. These surveys are showing that native vegetation is an important habitat for beneficial insects -- particularly when few crops are in the ground -- and that weeds and volunteer crop plants are harbouring pests. In addition, interception traps are placed on the boundary between crops and native remnant vegetation and between crops to quantify which insects are moving where and when. The data is being used to create spatial models and maps for pest/natural enemy interactions at field, farm and landscape scale. The results are starting to highlight the importance of maintaining and managing native vegetation remnants on farms. These remnants capture the private benefits of pest-control services, while contributing to public benefits such as biodiversity conservation and landscape amenity and stewardship. This project will help growers by providing guidelines for on-farm management to capture pest-control services. This may ultimately lead to keeping pest populations lower for longer, hence delaying insecticide use, decreasing the amount of insecticides needed and reducing production costs. □ GRDC Research Code CSE00051 More information: Dr Nancy Schellhorn, senior research scientist, CSIRO, 07 3833 5710, firstname.lastname@example.org; www.grdc.com.au/CSE00051 RESEARCH FINDINGS FROM Queensland's Darling Downs have shown that grain crops near native remnant vegetation contain more beneficial insects than those that are remote from native vegetation. In sites in Queensland, New South Wales and Western Australia, native plants are rarely ever found to harbour insect pests of crops but are sources of beneficial insects such as spiders, lace wings and lady beetles. Weeds often harbour pests and an important finding from previous research was that some landscapes appear to be less prone to invertebrate pest infestations. A three-year project, now in its second year, has MAINTAINING AND MANAGING NATIVE VEGETATION REMNANTS IS IMPORTANT FOR BENEFICIAL INSECTS.
GC Supplement - Soil biology initiative
GC Supplement - Crop protection