Measuring the benefits of cover crops in maize
Globally there is increasing interest and research in cover crops within cropping systems. The questions New Zealand growers are asking are, ‘what benefits can they bring to our systems and how can they be practically managed’?’ Allister Holmes, FAR’s Waikato based Research and Extension Manager, says weed suppression, improved soil health and reduced erosion, nitrogen fixation, improved biodiversity and the ability to provide in situ or cut and carry animal feed are just some of the reported benefits associated with the use of cover crops. However, he says, more work is required in order to understand how any effects, either positive or negative, can be managed in individual farm systems. “Recently FAR have increased their research into cover crops, focussing on their integration with maize systems. Much of this research has been based at FAR’s Northern Crop Research Site (NCRS) at Tamahere in Waikato, where currently six cover crop trials are underway. These trials are investigating issues such weed suppression, growth and development patterns, growing cover crops under maize, intercropping, establishment techniques and the impact of cover crops on following crops.” Cover crops and weed suppression Assessing different cover crops and their weed suppressive abilities. The trial, which is looking at faba beans, gland clover, oats and annual ryegrass, builds on a trial from last season, investigating a range of pre- and post-emergent herbicides and whether the weed control provided by cover crops could be used to reduce herbicide applications. The cover crops were sown in early winter and maize will be over sown in spring, before harvest assessments are carried out in autumn. Trevor James and Mike Trolove from AgResearch’s Farm Systems are undertaking this work. Growth and development patterns Observing growth and development patterns of a range of cover crop species were sown with two sowing dates, and […]