Earlier this year we learnt of an interesting project focusing on increasing biodiversity on vegetable farms. The aim of this joint project between A Lighter Touch, Vegetables NZ and Onions NZ is to reduce pest insects in crops by increasing the abundance of beneficial insects on vegetable farms, therefore reducing the need for insecticides.
Two suggested approaches for increasing biodiversity caught our attention. Over the last six months, we have been exploring their implementation at the MicroFarm. We are enormously grateful to Olivia Prouse for supporting our biodiversity journey so far. We are also grateful to Richard Mills from Summerfruit NZ for leading the way in Hawke’s Bay, and showing us the importance of just giving something a go! We also extend our gratitude to other growers engaging in this initiative, who have been sharing their experiences.
Mobile Insectaries
Mobile insectaries (moveable pods) aim to provide a source of shelter, nectar, alternative hosts and pollen (SNAP) for beneficial insects. The concentrated areas of SNAP support natural enemies, which can aid in pest control in vegetable crops. The moveable pods can be moved in and out of crops easily during the year.
Following the detailed ‘how to’ guide provided by ALT, with additional support from Olivia Prouse for plant selection, we built four moveable pods. Each pod has native five plants, all selected to flower at different times of the year. The species selected were mainly plants that had small flowers to provide habitat to small predatory wasps and other small insects which cannot feed on large flowers like commonly grown manuka.
We have been monitoring the pods to see what is flowering each month. While there is some maintenance required for weeding and watering, all plants survived the winter and are thriving this spring. We are excited to have species like Pimelea mimosa, which is a native daphne, naturally found only on Te Mata peak, and to have two species of Muehlenbeckia, which provides a food source for NZ native copper butterfly.
Annual Flower Strips
The aim adding annual flowering strips to a farm is to enhance above ground diversity. Again, this increases the diversity of natural pest insect enemies, providing additional pest control.
At the MicroFarm, we had two specific areas that made for good candidates for annual planting strips. The first is along our driveway, an area which is normally sprayed year-round for weeds. The second is under the irrigator guide cable, another area that gets sprayed, particularly in the spring and summer when the irrigator is running.
Using the ‘how to’ guide from ALT, we have planted a variety of annual flowers in these areas to see what might be suitable. In late September, we planted nine 10 m long plots of annual flowers, each with different combinations of species planted. The rest will planted by early December. We have been monitoring what is growing and what is flowering, and are excited to see insects present and a range of different colored flowers along the driveway.
What’s next?
We continue to monitor the moveable pods and annual flowering strips. We hope that our late plantings will persist through the summer and autumn. While not formally part of our main Carbon Positive project, it is a nice supplementary demonstration. We hope to showcase the ALT guides and provide some regional information about what may be suitable to grow (annuals and perennials) here in Hawke’s Bay. Read more about our journey in the latest A Lighter Touch newsletter here!