Groundnut/Maize/Cassava Intercrop Yield Response to Fallow Age, Cropping Frequency and Crop Plant Density on an Ultisol in Southern Cameroon

Abstract

Two methods of intensifying crop production in 'no-external-input' slash and burn crop fallow rotation systems: increased crop density and increased cropping frequency, were tested on an Ultisol in southern Cameroon. Two common fallow types, secondary forest (forest fallow) and young volunteer regrowth dominated by Chmmolaena odomta (bush fallow) were cleared, bumed and planted to a groundnut/maize/cassava!plantain intercrop for one year or two consecutive years. Maize, cassava and plantain were planted at the 'traditional' low density, at a 30% higher density and at high density with Cal/iandm mlothvrsus hedgerows as a soil fertility replenishment treatment. An increased maize density did not increase maize grain yield but reduced the groundnut grain yield in both years. Cassava root yield was not affected by planting density. In the second year of cropping, cassava yields were higher in bush fallow than in forest fallow. The cumulative maize grain yield of two consecutive years was unaffected by plant density in the bush fallow but was higher in the high plant density with C. mlothyrsus than in low plant density in the forest fallow. Cumulative groundnut grain yields were higher in the low plant density than in high density in bush fallow and higher in the low density than the high density and the C. mlorhyrsus system in forest fallow. Cumulative cassava root yields had the same response as groundnut grain yields in the forest fallow, yet in the bush fallow, high and low plant density out-yielded the C. mlothyrsus system. Yield increases through increased maize and cassava density were not possible. An increased total production through higher land use frequency appears possible at low plant density, yet not for maize. Alternative intensification options are discussed.

Synchrony of nitrogen supply and crop demand are driven via high maize density in maize/pea strip intercropping

“…Therefore, higher plant density may be adopted with intercropping compared to sole cropping. A previous study on intercropping found that increasing maize plant density reduced legume grain yield and did not increase maize grain yield 43 . In the present study, D3 reduced intercropped pea grain yield compared with D1 and D2, consistent with the trend in biomass, but the increased grain yield of maize with increasing density compensated for the loss of grain yield of intercropped pea.…”

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

“…For farmers in the region, early maturing maize is the first food harvested from first season fields and it is the first marketable product for income generation. Maize density in intercrops is low because the main crop, groundnut, does not tolerate shading (Hauser et al, 2006b). In peri-urban areas, sole maize crops are rapidly gaining importance because growers have easy access to markets for maize sales and the purchase of fertilizer.…”

“…Maize is grown as a minor component in the typical subsistence intercrop of groundnut/cassavalmaize (Hauser et al, 2006b) of the humid forest zone of West and Central Africa. However, farmers' interest in maize production is rapidly increasing because feed industries and breweries purchase dry maize grain in large quantities and the marketing of green cobs for fresh consumption is gaining importance, especially in urban and peri-urban areas.…”