Short- and Long-term Maize Yield Response toMucuna pruriensandPueraria phaseoloidesRelay Fallow and Biomass Burning Versus Mulching in the Forest Zone of Southern Cameroon

Abstract

Maize was relay cropped with the cover crops Mucuna pruriens or Pueraria phaseoloides for between one and seven consecutive years in three sites: Ngoungoumou, located in an area of low land use intensity (LUI), about 100 krn away from the next major market, and at Evendissi and Andok, in a medium LUI area, 15 to 20 krn away from the next major market. Maize performance was compared with that in a natural fallow system, with fallow biomass burned versus retained as mulch in both fallow types. Fallow type had no effect on maize density. After biomass burning higher maize densities were attained at the low LUI site. Maize cob production was affected neither by fallow type nor by biomass management. Across seven years of cropping, marketable cob production in the low LUI site was 38.5% higher in mucuna fallow than in natural fallow (p < 0.06). Differences at p < 0.05 were found in one out of seven years. In the medium LUI sites, mucuna and pueraria fallow increased marketable cob production by 70--132% (p < 0.001).Maize grain yield was closely related to the marketable cob production in all sites. In the low LUI site the cumulative maize grain yield over seven years was 30% higher in mucuna fallow than in natural fallow (p < 0.07), the difference being significant at p < 0.05 in only one year.In the medium LUI sites maize grain yield was 65% higher in mucuna fallow (p < 0.001) and 69-94% higher in pueraria fallow (p < 0.001). Burning biomass had a cumulative grain yield advantage of 33% at the low LUI site (p < 0.053), with significant (p < 0.02) differences in two out of seven years. Biomass burning had no effects on maize grain yield in the medium LUI sites. No interactions between fallow type and biomass management were found. Despite the lack of frequent significant advantages of the cover crop fallows in the low LUI site, the system can be recommended because it has the potential to increase food diversity and security; in the medium LUI sites farmers were immediately convinced of the benefits of the system and have since moved on to grow high value vegetable crops.

Estimating the Consequences of Fire Exclusion for Food Crop Production, Soil Fertility, and Fallow Recovery in Shifting Cultivation Landscapes in the Humid Tropics

“…Maize dry grain yields were estimated through plot harvests, grain separation, and dry matter determination (Norgrove et al 2003a; Hauser et al 2008). Plants were counted, cobs were removed, counted, husked, and weighed fresh.…”

“…Selection of plots was according to the following criteria: being located within the FMBA in the central block, which has medium population density, medium forest cover and in areas with the most prevalent soils (Ultisols), and average rainfall in order to reduce confounding factors; no use of external inputs; access to original data; a randomized comparison of burning versus fire exclusion with at least four replications, with yield data. Thus, we selected the following experimental plots as representative of these field types: maize grown after 4 years of fallow (Hauser et al 2008 ); plantain grown after 17 years of fallow (Norgrove and Hauser 2002a ). Due to theft and a requirement to abandon the latter field, a field of plantain after 20 years of fallow was additionally included (Hauser and Mekoa 2009 ; Hauser et al 2012a ).…”

“…Plots were manually weeded once during each growing period of the maize, as is local farmer practice and the plots were cultivated for two consecutive seasons. Maize stover was retained in situ after the first season and vegetation regrowth was slashed prior to replanting as before (Norgrove et al 2003 ; Hauser et al 2008 ).…”

“…In the 2-year fallow site, plots were harvested at 105 DAP in the first season and 98 DAP in the second season and in the 4-year fallow site, harvests were between 95 and 105 DAP. Maize dry grain yields were estimated through plot harvests, grain separation, and dry matter determination (Norgrove et al 2003a ; Hauser et al 2008 ). Plants were counted, cobs were removed, counted, husked, and weighed fresh.…”

Does Fallowing Cultivated Land Threaten Food Security? Empirical Evidence from Chinese Pilot Provinces

“…Partey et al and Cotta argued improved fallow system has real potential to secure enough food production using the cases in Sub-Saharan Africa and Peruvian Amazon [59,60]. Similarly, some studies from biology perspective also provide evidence with the statement that fallowing is an effective approach to improve fertility and hence increase food provision [61,62].…”