The effect of organic mulch on the growth and yield of Spinach (Spinacia oleracea L)
Abstract
An experiment was conducted in a greenhouse at the Luyengo campus of the University of Swaziland to determine the effect of organic mulch on the growth and yield of spinach. The experiment was conducted between the months of January and February, 2017. The experiment was a completely randomized design (CRD), with treated sewage mulch (TSM) and organic compost mulch (OCM) as treatments. The no mulch (NML) was used as a control. Spinach seedlings were planted at a spacing of 15 cm within rows and 30 cm between rows. Weeding and pest control measures were done uniformly across the treatments, when and as required. The data collected included the percentage moisture retained by the different treatments on the soil, growth parameters (leaf width, leaf length, leaf number, leaf area, plant height) and yield at harvest . The results displayed a significant difference (P<0.05) between the treatments in terms of the moisture retention properties. Organic compost much recorded the highest mean percentage moisture retention (22.9%), followed by treated sewage mulch (20.9%) and no mulch recorded the lowest percentage moisture retention in the soil (14.4%). All the growth parameters were higher for spinach growth under TSM, followed by that grown under OCM. They were lowest under spinach grown under no mulch. The differences in mean for parameters were significant (p<0.05). The yield also varied across the treatments as TSM had a dry mass of 43.0 g, followed by OCM at 23.4 g and the no mulch treatment recorded a dry mass of 20.9 g. The results showed that mulching improved the performance of the spinach plants in terms of plant growth, moisture retention and yield .
Keywords
Download Options
Introduction
Spinach is one of the significant vegetables grown in the Kingdom of Swaziland. This green leafy vegetable is principally believed to have come from south-western Asia [1]. Production of spinach in the country is dominant on communal land where subsistence farming is practiced [2] . Subsistence agriculture is characterized by small scale production on a few square metres of land, mainly for the purpose of providing food for the families [3]. Spinach production is also important due to its health benefits as it supplies the body with nutrients such as Vitamin A, C and K. Vege tables such as spinach are also beneficial because they form a significant constituent of the Swazi nation’s diet, because it can be served in a variety of dishes [4]. Low soil fertility intensity is one of the major contributors to the little productivity of vegetable crops in Swaziland. The fertility of the soil can be improved by the application of organic as well as inorganic fertilisers. The use of inorganic fertilisers proves to be very expensive and may also cause other side effects in the soil such as soil salinity [5].The use of organic methods such as composting, to restore soil fertility and soil physical properties has gained attention in the agricultural sector [6].
Compost has a similar composition to the soil organic matter thus it also enhances the physical properties of the soil such as the soil structure as well as the soils moisture and nutrient retention abilities [7]. Compost also helps maintain the nutrients in the soil for elongated periods of time since it is composed of differently sized constituents, which break down in the soil at varying decomposition rates, making the nutrients to be constantly available [8].Treated sewage sludge can also be used as a compost [9]. Sewage sludge contains vital plant nutrients as well as organic matter which may be utilized in crop production such as spinach, to substitute as well as increment the use of synthetic fertiliser in the country [10]. It enhances the physical, chemical and biological properties of the soil [11]. Plant nutrients contained in sewage sludge play an important role in the improvement of plant biomass [12]. The objective of the study was to determine the effect of compost on the growth and yield of spinach.
Conclusion
The results showed that the growth rate and yield of spinach plants grown on the treated sewage mulch and the organic compost mulch were better when com pared to that of spinach plants grown without mulch. Treated sewage mulch produced spinach plants with the highest growth rate as the plants exhibited a higher mean leaf area, leaf width, leaf length leaf number and plant height. The dry yield across the treatments was 43.0 gin the treated sewage mulch, 23.4 gin the organic compost mulch and 20.9 gin the no mulch treatment. The treated sewage waste resulted in higher yield of spinach compared to all the other treatments. It is concluded that the mulch ha d a positive effect on the yield of spinach.
