EFFECT OF COMPOSTED MUNICIPAL SOLID WASTE AND NPK FERTILIZER ON THE GROWTH AND YIELD OF MAIZE (ZEA MAYS L) IN NSUKKA

ABSTRACT

Municipalities are facing a growing problem of how to safely dispose off their wastes. Municipal solid waste (MSW) is waste from households, commercial centres, institutions (school, offices). Composting is used to reduce huge pile of biodegradable MSW and convert it into value added product like manure and biogas. Inorganic fertilizer such as NPK also exerts strong influence on plant growth, development and yield. Two year experiments were conducted in the Teaching and Research Farm of Department of Crop Science,  Faculty of Agriculture, University of Nigeria, Nsukka to determine the response of maize to MSW compost and NPK fertilizer application. A 4 x 4 factorial experiment in Randomized Complete Block Design (RCBD) with three replications was used for the study. The two factors were MSW (0, 1.0, 1.5 and 2.0 t/ha) and NPK (20:10:10) (0, 100,

200 and 300 kg/ha). The following data were collected: leaf area, Plant height, stem girth, number of leaves, days to first tasseling, plant fresh weight, plant dry weight, ear weight, ear height, ear circumference, cob weight, 100 grain weight, grain yield and harvest index. Data collected were subjected  to  analysis  of  variance  (ANOVA).  The  means  were  separated  using  Fisher’s  least significant difference (F-LSD). Plant height, leaf area, number of leaves and stem girth increased with increase in NPK and MSW rates while days to tasselling and silking was reduced. The 100 grain weight, grain yield per hectare and harvest index were significantly increased with increase in MSW and NPK rates. Proximate composition followed the same trend apart from carbohydrate content which decreased with increase in application rates of MSW and NPK.  Application of either

2000 kg/ha MSW or 300 kg/ha NPK gave the highest yield of maize in 2011 and 2012. Complementary application of MSW and  NPK  was  significantly higher  than  sole  application. Combination of 2.0 t/ha MSW with 300 kg/ha NPK had significantly higher effect than other treatment combination in both years and were found satisfactory for achieving high yields in maize. It  is recommended that  further research should be carried out to determine the optimum rates required for maize production since performance increased up to the highest rates of MSW and NPK fertilizer.

INTRODUCTION

Urban areas in Nigeria are facing a growing problem of how to safely dispose off their solid wastes. Bryan and Morton (2007) defined municipal solid waste (MSW) as waste from multifamily, commercial, and  institutional (schools and government offices) centre. This definition excludes many materials that are frequently disposed with MSW in landfills including combustion ash; water waste treatment residuals, construction and demolition waste, and non hazardous industrial process waste (U.S EPA, 2007).

In most developing countries like Nigeria, MSW are used as landfills or dumped in sites where people no longer use. In some sites where MSWs are dumped, they are burnt when the heap is large and overflows. Many strategies are being adopted to dispose wastes but most of them are neither safe for the environment nor sustainable for nutrient conservation (Rizwan et al., 2006).

Municipal solid waste is composed of prutesible (biodegradable) and non prutesible (non biodegradable) constituents. Prutesible fraction includes waste from kitchen, paper industries, wood scraps etc. Non prutesible includes waste from rubber, automobile and polythene industries etc.

Oyinlola (2001) reported that the organic components account for about 76% of total MSW in Nigeria. Anton et al. (2005) stressed that in order to minimize environmental impacts and the loss of organic resources, there should be measures taken to increase and improve sorting at source of origin, recuperation and recycling, including compositing of organic and green MSW. Organic MSW is described as house hold wastes and other wastes which because of their nature of composition, are similar to house hold wastes, capable of undergoing anaerobic or aerobic decomposition, excluding green MSW from gardens and parks, which include tree cuttings, branches, grass and wood (European Commission, 2001).

Composting is one of the best solutions to reduce the huge pile of organic waste and its conversion to a value added product. It is one of the major recycling processes by which nutrients present in organic materials are returned back to the soil in plant available form (Inckel et al., 1996). The  application  of  organic  manure  to  soil  provides  benefits  including  improving  the  fertility, structure, water holding capacity of soil, organic matter in the soil and reducing the amount of synthetic fertilizer needed for crop production (Phan et al., 2002; Blay et al., 2002).

The low fertility status of most tropical soils hinders crop production as most crops have a strong exhausting effect on the soil. It is generally observed that crops fail to produce reasonably in

plots without adequate nutrients. Inorganic fertilizer such as NPK exerts strong influence on plant growth, development and yield (Stefano et al., 2004). The availability of sufficient nutrients from inorganic fertilizer leads to improved cell activities, enhanced cell multiplication and enlargement and luxuriant growth (Fashina et al., 2002). However excessive or continual use of NPK fertilizer will lead to loss of soil fertility due to improper use of it which has adverse impact on agricultural productivity, cause soil degradation and even contaminate underground water resources.

Wheat, rice and maize are the most important cereal crops in the world but maize is the most popular due to its high yielding and ease of processing (Jaliya et al., 2008). Maize is a major source of carbohydrate. Other nutrients which can be derived are protein, iron, vitamin B, and minerals. Maize is also utilized in the livestock, textile and pharmaceutical industries. Maize has immense potential in the tropics and yields up to 7.5t/ha of grain if the crop is properly managed (Kolawole and Joyle, 2009). Unfortunately, yields are still generally below 5t/ha in Nigeria (FAO, 2007). Yield differences within temperate areas have  been attributed to  low  nutrient  status of tropical soils especially nitrogen, phosphorus and potassium resulting from the practice of slash and burn farming system associated with bush fallow and excessive leaching of the soil nutrients. This system is presently unsustainable due to high population pressure and other human activities which have resulted in reduced fallow period (Steiner, 1991). This study was conducted to achieve the following objectives:

1.  Determine the response of maize to MSW compost

2.  Evaluate the response of maize to combined effects of MSW compost and NPK fertilizer application,

3.  Determine the effect of MSW compost and NPK fertilizer on the nutrient composition of maize.

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