Production of vegetables in the smallholder sector of sub-Saharan Africa (SSA) is affected by
poor soil fertility with nitrogen (N) being the most limiting nutrient. Continued nutrient
mining without adequate replenishment has led to a corresponding decline in soil fertility and
crop yields due to failure by farmers in SSA to purchase inorganic fertilisers. Leguminous
multipurpose tree (MPT) prunings have widely been promoted as alternative sources of N but
nutrient release is affected by type of MPT and quality attributes such as total N, total
carbon(C), lignin, polyphenols and C:N ratio. The aim of this study was to evaluate various
MPTs which can provide adequate N to Brassica napus L. (rape) which is a short season but
high N demanding crop harvested over multiple times. An experiment was therefore,
conducted at the Midlands State University to determine the yield response of rape to legume
prunings of different quality. The experiment was arranged as a 2 x 7 factorial treatment
structure in a randomised complete block design (RCBD) with placement method (mulching
or soil incorporated) being the first factor and pruning type (Tithonia diversifolia, Gliricidia
sepium, Calliandra calothyrsus, Acacia karoo, Acacia angustissima, Leucaena pallida and
Leucaena trichandria) being the second factor. The tree prunings were applied at a rate to
achieve 150 kg N ha-1. The crop was transplanted at 4 weeks after sowing. Data on LAI, fresh
and dry weight readings as well as leaf chlorophyll readings were taken fortnightly and
subjected to an analysis of variance (ANOVA). Incorporation of prunings achieved the
highest total dry mass of 1,046 t ha-1 compared to mulching which had 0.580 t ha-1. The two
Acacia species achieved the lowest dry mass (DM) yields while G.sepium and C.calothyrsus
achieved the highest DM yields. A. angustissima and A. karoo achieved the lowest total fresh
leaf yield of 1.681 and 1.910 t ha-1 respectively while L. trichandria was the highest yielding
at 1.996 t ha-1 for mulched treatments. Under incorporated treatments L. trichandria and A.
angustissima gave the lowest total yields of 2.206 and 2.033 t ha-1 respectively while T.
diversifolia was the highest yielding at 2.377 t ha-1 fresh weight. These results showed that
soil incorporation gives the highest yields for fresh and dry weight. From the results it can
therefore be recommended that farmers should use T. diversifolia and L. trichandria prunings
over the Acacia species prunings for high fresh weight yields.
SSA, R (2021). Effect of different multipurpose tree prunings and placement method on the growth and development of rape (Brassica napus L.). Afribary.com: Retrieved May 08, 2021, from https://afribary.com/works/effect-of-different-multipurpose-tree-prunings-and-placement-method-on-the-growth-and-development-of-rape-brassica-napus-l
Research, SSA. "Effect of different multipurpose tree prunings and placement method on the growth and development of rape (Brassica napus L.)" Afribary.com. Afribary.com, 04 May. 2021, https://afribary.com/works/effect-of-different-multipurpose-tree-prunings-and-placement-method-on-the-growth-and-development-of-rape-brassica-napus-l . Accessed 08 May. 2021.
Research, SSA. "Effect of different multipurpose tree prunings and placement method on the growth and development of rape (Brassica napus L.)". Afribary.com, Afribary.com, 04 May. 2021. Web. 08 May. 2021. < https://afribary.com/works/effect-of-different-multipurpose-tree-prunings-and-placement-method-on-the-growth-and-development-of-rape-brassica-napus-l >.
Research, SSA. "Effect of different multipurpose tree prunings and placement method on the growth and development of rape (Brassica napus L.)" Afribary.com (2021). Accessed May 08, 2021. https://afribary.com/works/effect-of-different-multipurpose-tree-prunings-and-placement-method-on-the-growth-and-development-of-rape-brassica-napus-l