Effect of Cogongrass (Imperata cylindrica L.) root extract on earthworms, arbuscular mycorrhizae fungi spore, and growth of upland rice (Oryza sativa L.) for local Kambowa variety

Abstract

Earthworms have the ability to create new conditions in the soil environment and modulate the growth of beneficial soil microbial populations. Imperata releases exudate which creates less suitable soil conditions for growing food crops and horticulture. This study aims to: (i) study the effect of the concentration of cogongrass root extract on the abundance of earthworms and arbuscular mycorrhizal fungi spores-(ii) to determine the effect of the soil-extract mixture engineered using earthworms on the upland rice growth for local Kambowa variety. The first experiment, extracts of cogongrass roots were made into five concentration levels, namely 0%, 20%, 40%, 60%, and 80%. Each concentration was mixed with soil from cogongrass land in a different vermireactor. In reactor, earthworms were released that had emptied their stomach contents, and were allowed to manipulate the mixture until the vemicast covered part of the soil surface. As a result, the total earthworms in all reactors were relatively the same, and the total spores of arbuscular mycorrhizal fungi in the soil treated with a concentration of 60% was the most. The second experiment, the upland rice seedlings were grown on engineered soils. The differences in height, leaf area, number of tillers, panicle length, and total spikelet’s per panicle were significantly, except for leaves number, wet weight, dry weight, and percentage of spikelet filled. In conclusion, earthworms as potential ecosystem engineers are utilized in ecological engineering of soil quality in land dominated by reeds vegetation for the development of upland rice cultivation areas, particularly the local varieties of Kambowa.