The impact of conventional and organic farming on soil biodiversity conservation: a case study on termites in the long-term farming systems comparison trials in Kenya

Abstract

Background: A long-term experiment at two trial sites in Kenya has been on-going since 2007 to assess the effect of organic and conventional farming systems on productivity, profitability and sustainability. During these trials the presence of significant numbers of termites (Isoptera) was observed. Termites are major soil macrofauna and within literature they are either depict as 'pests' or as important indicator for environmental sustainability. The extent by which termites may be managed to avoid crop damage, but improve sustainability of farming systems is worthwhile to understand. Therefore, a study on termites was added to the long-term experiments in Kenya. The objectives of the study were to quantify the effect of organic (Org) and conventional (Conv) farming systems at two input levels (low and high) on the abundance, incidence, diversity and foraging activities of termites. Results:The results showed higher termite abundance, incidence, activity and diversity in Org-High compared to Conv-High, Conv-Low and Org-Low. However, the termite presence in each system was also dependent on soil depth, trial site and cropping season. During the experiment, nine different termite genera were identified, that belong to three subfamilies: (i) Macrotermitinae (genera: Allodontotermes, Ancistrotermes, Macrotermes, Microtermes, Odontotermes and Pseudocanthotermes), (ii) Termitinae (Amitermes and Cubitermes) and (iii) Nasutitiermitinae (Trinervitermes). Conclusions:We hypothesize that the presence of termites within the different farming systems might be influenced by the types of input applied, the soil moisture content and the occurrence of natural enemies. Our findings further demonstrate that the organic high input system attracts termites, which are an important, and often beneficial, component of soil fauna. This further increases the potential of such systems in enhancing sustainable agricultural production in Kenya.

Termite-Induced Injuries to Maize and Baby Corn under Organic and Conventional Farming Systems in the Central Highlands of Kenya

“…The study aims to compare the performance of organic and conventional farming systems in the tropics on productivity, profitability and sustainability. However, in the trial plots, the presence of termites, as major macrofauna, was reported repeatedly and confirmed by a first study [1].…”

“…Anyango et al [1] could show that the termite abundance and diversity were generally higher in Org-High at both experimental sites (Chuka and Thika) and in both maize seasons (2014 and 2015). Average termite abundance and diversity were lower in all the other farming systems.…”

“…Chuka is more prone to heavy rainfall and flooding than Thika (own data, see [13]), which would shift termite activity to deeper soil layers and prevent surface foraging. This could also explain the higher numbers of termites found in the subsoil (20–40 cm depth) at Chuka than in the substrate layer [1]. Ref.…”

“…The soldier genus identification was later confirmed at the National Museum of Kenya, Nairobi, using the standard determination keys [17,18]. The detailed results can be found in [1].…”

“…The objectives of the studies were to compare organic and conventional farming systems and more, specifically: (i) to determine the incidence of different injuries (lodging and tunneling) at different crop stages; and (ii) to determine the termite species causing the injuries. The study hypothesis was that termite pest status is influenced by farming systems, and as termites were observed to be more abundant in the organic systems with high inputs of fertilizer and irrigation (see [1]), a greater incidence of injuries was expected in this farming system than in the others.…”