Clover species a solution for drought-prone areas?

New clover species a solution for drought-prone areas?

Some plants used in pastures find it more difficult to acclimatise to summer drought conditions than others.

New Zealand’s pasture-based industries depend on clover and other legume species to provide the essential nitrogen needed by the grasses eaten by grazing animals, but current species of clover do not cope well under drought conditions.

Dr Rainer Hofmann, Senior Lecturer in Plant Biology at Lincoln University is one of the scientists in the race to find more suitable clover species that will both survive and produce well in low rainfall areas of the country, such as Canterbury, Marlborough, Hawke’s Bay and Wairarapa.

Dr Hofmann’s team from the Faculty of Agriculture and Life Sciences at the University compared two different clover species for their ability to maintain growth under drought conditions and found that one adapted better to short-term simulated drought conditions than the other.

“We were delighted that our results showed that strawberry clover has promise as a legume to complement or be an alternative to white clover in grassed pasture,” said Dr Hofmann.

“With the increased frequency of summer droughts experienced in New Zealand, it is important that we work to find as many viable alternatives as possible for farmers to choose from, so that the particular cultivar chosen is one that best suits their particular environmental conditions. Our research is a significant contribution to the search for drought-resistant clover cultivars.”

The legume white clover is commonly grown with pasture grasses. This system works well under optimal growing conditions but white clover often shows growth deficiencies under marginal and limiting environmental situations such as low soil moisture.

This research investigated the performance of the closely related plant, strawberry clover.

White clover and strawberry clover plants were investigated in a trial that compared the two species, at two different moisture levels; the control set of plants was watered to within 5% of field capacity and the drought-treated plants were watered to 5% (by weight) above the permanent wilting point.

A number of different plant development traits were measured at the end of the drought including leaf size, petiole (leaf attachment) length, relative leaf area, water content and plant biomass (dry weight).

Results showed that strawberry clover leaf growth adjusted better than white clover under drought conditions with white clover showing reductions in all plant traits measured,” said Dr Hofmann.

“Future research under field conditions and under limiting water supply could investigate leaf and stolon development as well as long-term plant performance and survival to test the use of strawberry clover as a complement or alternative to white clover in grazed pastures,” said Dr Hofmann.

“This project began when a colleague of mine at Lincoln suggested I use these two species as part of a third-year student class in plant science. The students were placed in groups and asked to design an experiment that would reveal whether there were any significant differences between these species for drought survival.

“When we compared the students’ efforts with our previously designed experiment, they showed an excellent grasp of the necessary parameters and the scientific rigor required for such an experiment

“We subsequently used their practical assistance under the supervision of a visiting Chinese scholar who conducted our experiment.”

This research was presented at a New Zealand Grasslands Association conference where strawberry clover’s potential as an alternative plant for drought-prone areas was recognised.

ENDS

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