Abstract:
In ground nut cultivation, the period of up to one month of plant growth is a critical period of
weed growth and competition with weeds. The objective of the study was to develop crop residue
based mulching pellets for weed control, improve the soil, the yield and yield parameters of
groundnut. An experiment was carried out during yala season in 2023 at the Grain Legume and
Oil Crops Research and Development Centre (GLORDC), Angunukolapelessa (Agroclimatic region
DL1b) in the Hambantota District of Southern Sri Lanka. The experiment was designed as a
Randomized Complete Block Design (RCBD) with five treatments with three replicates. The
composition of the mulching pellet was three parts guinea grass, two parts banana leaves, two
parts groundnut husk and three parts maize cob biochar. The proportions of the material were
selected based on the final physio-chemical characteristics of the pellets. The physical properties
of the pellets water absorption (k=1.82), density (0.44 gcm-1), average length (22.43mm),
average diameter (5.58mm) and average weight (5.09g). Chemical properties were pH (7.75),
electric conductivity (1.755 dS/m) and N:P:K ratio (0.33: 0.23:6.9). Treatments were T1
(Application of mulching pellet), T2 (Groundnut husk mulch), T3 (Guinea grass leaves mulch), T4
(Banana leaves mulch) and T5 (Without mulch) and all were applied at 10t/ha rate. After 7weeks,
soil moisture retention was improved in T1 treatment (45.3%) than control (30.67%), therefore
crop residue based mulching pellet can be used as the ideal mulch to maintain soil moisture. The
initial soil pH, EC and Organic matter content were 6.86, 3.65mS/cm and 1.684. After two months
of treatment application values were 5.5, 3.9, 2.01 in T1 and 5.86, 0.09, 0.97 in T5. 04 weeks after
planting the count of different types of weeds as grasses, sedges broad leaves were observed
significantly difference (<0.05). The overall weed count was highest in T5 and lowest in T1. In
grasses the highest values were recorded in T5 (83.42a), lowest in T1, T2, T4 (23.5c, 37.7bc and
50.7bc) and highest in T5 (139a). In sedges, the highest were recorded in T4, T5 (107.3a, 130.3a)
and the lowest in T1 (44.7b). In broad leaves the highest were in T3, T4, T5 (59ab, 51.3ab, 83.3a)
and the lowest in T1 and T2 (20b, 30b). The highest pod weight per plant (42.99a), number of
mature pods per plant (70.67a) and 100 seed weight (22.93a) were recorded in T1 and lowest
yield values were recorded in T5 (20.21b, 36.67b and 16.82b). Application of all the tested mulches
gave best results, instead that the crop residue based mulching pellet was observed most better
qualities than tested other mulches, therefore with further improvements the mulching pellet can
be recommended to farmers as a sustainable and innovative solution to environmentally friendly
agricultural sector in the future.
