Yields of crops on a rhodic ferralsol in southern Brazil in relation to no-tillage crop rotation systems
Even though no-tillage, crop rotation management systems have been accepted as useful for sustaining crop production, there is the need to identify which crops can be used for such rotations. This study evaluated the dry matter and grain yields of eight winter and two summer crops (maize, Zea mays L. and soybean, Glycine max L.) grown in rotation from 1985 to 1987 and from 1989 to 1990. The experiment was set up as a randomized complete block design with three replicates of each treatment. From 1985 to 1987 the winter crops were mucuna (Mucuna aterrima Piper & Tracy), pigeon pea (Cajanus cajan (L.) Millsp), rye (Secale cereale L.), oat (Avena sativa L.), pisum (Pisum sativum L.), wheat (Triticum aestivum L.), crotalaria (Crotalaria juncea L.) and black oat (Avena strigosa Schieb). In 1988 wheat was grown on all plots and from 1989 to 1990 the following winter crops were grown: lathyrus (Lathyrus sativus L.), lupin (Lupinus albus L.), rye (Secale cereale L.), oat (Avena sativa L.), lupin + black oat (Lupinus albus L. + Avena strigosa Schieb), wheat (Triticum aestivum L.), crotalaria (Crotalaria juncea L.) and black oat (Avena strigosa Schieb). The results showed that in absolute terms the dry matter and grain yields were highest in 1985 and diminished in 1986 and 1987. The grasses had higher yields than the legumes within each year. Also during each year the dry matter yields were higher than the grain yields of each crop. Higher yields were obtained when grasses followed soybean than when they followed maize in rotation. From 1985 to 1987 maize produced higher yields under crotalaria, mucuna and rye than under the rest of the rotations whereas soybean performed better under black oat, rye and oat than under the legume rotations. In the 1989 rotation maize also did better after legumes than grasses whereas soybean grown after grasses outperformed those grown after legumes. Crotalaria performed best with maize whereas oat performed best with soybean. Maize yield was less affected than soybean yield by changes in the fertility status of the soil.
Keywords: Crop rotation; Maize; Soybean; Soil fertility; No-tillage; Crop yields
Agro- Science Vol. 4 (2) 2005: pp. 1-7