Making Mulch Ado Of Ant Hills

Ants, which account for half of all insect biomass in the world, are beneficial to agriculture in more ways than one.

AsianScientist (Mar. 30, 2017) – When ants create anthills, it helps the soil to retain moisture. These findings have been published in the Soil Science Society of America Journal.

Ants can be annoying little insects. In your home, they make army-like lines to any crumbs on your floor. In your home’s frame, carpenter ants can do a job of eating away your walls. But what about outside? Do ants play a positive role in your garden or farm?

Research undertaken by scientists in China reveals that ants are hardworking and beneficial insects. In the activities of their daily lives, ants help increase air, water flow, and organic matter in soil. The work done by ants even forms a type of mulch that helps hold water in the soil.

As soil-dwelling ants build their homes, they place the soil they remove on the surface, creating clumps that researchers call aggregate mulches.

“In addition to creating the aggregate mulches, ants help the soil environment by bringing down food sources from outside,” said soil scientist Dr. Li Tongchuan from Northwest A&F University. “Types of food include the bodies of insects, leaves, sugar water, and the ‘honeydew’ of aphids. The big diameter of the nest channels (4.1-6.6mm) and the chambers also can improve the transport of air with frequent ant activities.”

Furthermore, Li and his team found that ant-made aggregate mulches could help retain water in agricultural fields. In other words, these aggregates can act like any other mulch, preserving moisture in the soil, under certain conditions.

“Minimal attention has been paid to the effects of ant activities on soil [water] evaporation thus far,” said Li. “Ants represent half of the global insect biomass, and these mulches could be playing an important role in soil moisture, soil health, and agricultural field efficiency.”

According to the study authors, gravel has been used in China as an effective mulch to conserve water. However, in the Northern Loess Plateau region, gravel is difficult to come by. Instead, the region depends on soil-dwelling animals like ants to reduce the evaporation of water.

“Before the Grain for Green Project [to promote the use of soil-dwelling animals], cropland was the main land use,” said Li. “Plowing can severely damage ant nests. [The project called for the] abandonment of agricultural land in these areas. The result was less disturbance and a substantial increase in vegetation cover, which promoted the development of ant colonies.”

The researchers found that the percentage of soil moisture affected how well the ant aggregate mulch performed. At a near-average level of soil moisture, 12.6 percent, ant aggregate mulch works well. They found that evaporation of water from the soil surface significantly decreased with increasing aggregate mulch thickness.

One downside to ant-made aggregate mulches is that they disintegrate with rainfall. However, ants tend to enlarge their nests by making new chambers after a rainfall, producing more aggregate mulches after rains.The article can be found at: Li et al. (2017) Characteristics of Soil Evaporation and Temperature under Aggregate Mulches Created by Burrowing Ants (Camponotus japonicus).

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Source: American Society of Agronomy; Photo: Li Tongchuan.Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

#Agriculture #Ants #China #Chinese Academy of Sciences #Nature #Northwest A & F University #Shenyang Agricultural University

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.