Tag: chemical composition
Yield and chemical composition of frankincense from Boswellia papyrifera cutting-based planted trees
The population of Boswellia papyrifera is rapidly declining despite its ecological, socio-economic, and cultural importance, highlighting the need for urgent conservation action. While vegetative propagation shows promise, the yield and chemical composition of frankincense from such plantations are not well understood. This study evaluated frankincense yield and chemical composition across three treatments: (i) trees propagated from branch cuttings with no prior tapping, (ii) naturally grown trees rested from tapping for three years, and (iii) naturally grown trees continuously tapped for three years. Yield was measured across nine tapping rounds on 15 trees (five per treatment). Results revealed that trees propagated from cuttings produced significantly higher annual frankincense yields than continuously tapped trees in natural stands. The average yield per tapping round followed a unimodal pattern, peaking at the sixth round before declining over the final three rounds for both planted and naturally grown trees rested for three years. Additionally, frankincense from planted trees exhibited significantly higher moisture content and bioactive compounds than from natural stands. These findings underscore the potential of vegetatively propagated B. papyrifera for frankincense production, and we recommend adopting vegetative propagation and planting of B. papyrifera to enhance its yield and chemical compositions in dryland areas.
Alley cropping of maize with calliandra and leucaena in the subhumid highlands of Kenya: Part 2. Biomass decomposition, N mineralization, and N uptake by maize
A major challenge in developing agroforestry approaches that utilize tree-leaf biomass for provision of N to crops is to ensure synchrony between the N released from decomposing prunings and N demand by crops. A study was conducted in the subhumid highlands of Kenya to assess the rate of decomposition and mineralization of soil-incorporated Calliandra calothyrsus Meissner (calliandra) and Leucaena leucocephala (Lam.) de Wit (leucaena) tree biomass and maize roots (Zea mays L.) both in an alley cropping and a sole cropping system. The amount of mineralized N peaked four weeks after planting (WAP) maize in all the treatments during both seasons of 1995. Cumulative mineralized N at week 20 ranged from 114 to 364 kg N ha1 season1, the absolute control treatment giving the lowest and the prunings-incorporated treatments giving the highest amounts in the two seasons. Total N uptake by maize, ranging from 42 to 157 kg ha1 season1, was lowest in the ‘alley-cropped, prunings-removed’ treatments, and highest in the ‘non alley-cropped-prunings-incorporated’ treatments. The apparent N recovery rate by maize was highest in the fertilizer applied treatments in the two seasons. Decomposition rate constants (kD) ranged from 0.07 to 0.21 week1, and the rates among the different plant residues were as follows: leucaena < calliandra < maize roots. Nitrogen release rate constants (kN), ranging from 0.04 to 0.25 week1, followed a similar pattern as the rate of decomposition with leucaena releasing the highest amount of N followed by calliandra and lastly by maize roots
Near infrared calibration of chemical constituents of Cajanus cajan (pigeon pea) used as forage
Near infrared reflectance spectroscopy (NIRS) was used to predict quality parameters in Cajanus cajan used as forage for animals. Crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), crude lipid (CL) and organic matter (OM) were determined by chemical methods. The set of samples for analysis was selected using the software SELECT on the basis of the NIR spectra of samples from field plots and consisted of branches and leaves of Cajanus cajan, harvested in two contrasting locations in Zimbabwe. The samples were scanned and screened using an NIR Systems Model 5000 monochromator; 48 samples were used to calibrate and to cross-validate the equations derived. Equations for predicting chemical composition of the species under study were calculated using scores from partial least squares (PLS) as independent variables. Cross-validation procedures indicated good correlations between laboratory values and NIRS estimates. NIRS calibrations obtained from this study could be utilised in current and future programmes for evaluating the quality of Cajanus cajan forage for animal nutrition.