Amendment ofTephrosiaImproved Fallows with Inorganic Fertilizers Improves Soil Chemical Properties, N Uptake, and Maize Yield in Malawi

Abstract

Maize production in Malawi is limited mainly by low soil N and P. Improved fallows of N-fixing legumes such asTephrosiaandSesbaniaoffer options for improving soil fertility particularly N supply. The interactions ofTephrosiafallows and inorganic fertilizers on soil properties, N uptake, and maize yields were evaluated at Chitedze Research Station in Malawi. The results indicated that the level of organic matter and pH increased in all the treatments except for the control. Total N remained almost unchanged while available P decreased in all plots amended withT. vogeliibut increased inT. candidaplots where inorganic P was applied. Exchangeable K increased in all the plots irrespective of the type of amendment. The interaction of N and P fertilizers withT. vogeliifallows significantly increased the grain yield. The treatment that received 45 kg N ha−1and 20 kg P ha−1produced significantly higher grain yields (6.8 t ha−1) than all the other treatments except where 68 kg N ha−1and 30 kg P ha−1were applied which gave 6.5 t ha−1of maize grain.T. candidafallows alone or in combination with N and P fertilizers did not significantly affect grain yield. However,T. candidafallows alone can raise maize grain yield by 300% over the no-input control. Based on these results we conclude that high quality residues such asT. candidaandT. vogeliican be used as sources of nutrients to improve crop yields and soil fertility in N-limited soils. However, inorganic P fertilizer is needed due to the low soil available P levels.

Efficacy of Aqueous Extracts from Syzygium aromaticum, Tephrosia vogelii, and Croton dichogamus against Myzus persicae on Brassica oleracea in Northern Tanzania

“…For instance, Grzywacz et al [36] and Kamanula et al [38] found that the effectiveness of the pesticidal plant extracts could be attributed by the presence of bioactive chemical compounds in those plants. T. vogelii, which was found effective in reducing M. persicae population in the present study, has been reported previously to manage ticks, lice, and flies on livestock and crops in the fields [24,40], Plutella xylostella and Trichoplusia ni [6]. Belmain et al [41] discovered the presence of rotenone in T. vogelii, which should be accountable for the insecticidal efficacy against M. persicae on the B. oleracea field.…”

Plants in the Genus Tephrosia: Valuable Resources for Botanical Insecticides

“…T. candida proved to be one of the most satisfactory green manures because it can flourish in poor soil for several years and has a dense foliage [ 103 ]. T. candida fallows alone can raise maize grain yield by 300% [ 104 ]. In South Rwanda, T. vogelii and Cajanus cajan were intercropped with Sorghum bicolor during the long rainy season.…”

Qualitative Cost-Benefit Analysis of Using Pesticidal Plants in Smallholder Crop Protection

“…This raises the need for better awareness and education, but also highlights the importance of promoting lower risk pesticides such as pesticidal plant extracts. The lower risks of using plant extracts were explained by farmers, who reported that it was not necessary to take antidotes after spraying plant extracts to treat chest pain, an effect linked with effects acquired from spraying synthetic pesticides whereby drinking milk is often used as an antidote [38].…”