Composting as tool to Reduce, Reuse and Recycle Organic Solid Waste

Composting as tool to 3 R on Organic Solid Waste

Composting is an easy way to recycle your garden and kitchen waste. It provides a useful means of transforming biodegradable waste, such as fruit, vegetables, teabags and garden waste, into a product that can improve soil structure and nutrient levels. Even if you are not into gardening, you are reducing the amount of waste that goes to landfill so you are still helping the environment as well as your pocket. It can be easier and cheaper than bagging these wastes or taking them to the transfer station.

Composting is a natural process, so natural, it happens everyday around you. Organic materials rot or biodegrade naturally into a brown/black crumbly material that can be used in your garden as a soil improver or natural fertilizer. This change occurs thanks to the insects, worms (‘chompers’), fungi and bacteria. Then other microorganisms (‘heaters’), which the human eye cannot see but live in the soil, start their work. Their combined efforts help turn organic waste into the compost. Compost provide a number of benefits to soil, including:

i)   Improved soil fertility

ii)  Improved soil structure

iii) Improved water-holding capacity

iv) Reduced erosion

      v)  Reduce levels of plant pathogens, insects and weeds

How to start Composting?

The choosing of composting methods will determine what you need to start a composting. If you prefer to use a holding unit method (bins), there has a different bins you can work with (plastic bin, drum can, wire, wood posts, etc.) and its availability will depend on the market.

Locate the compost bin (or heap) in a position that is convenient to your house — make using it easy for yourself! Try to choose a sunny spot and the soil should be free of draining. This will ensure your compost will be moist but well aerated and will encourage insect activity and ultimately better compost (In hot countries, compost bins can overheat and dry out – something that we do not have to worry about!) Loosen up the soil first and place bird cage wire on the ground (this is available from most hardware and DIY stores) and locate the compost bin on top of this.

How to make good compost?

Then it is all in the mix, so you must get the right balance between the green waste and brown waste, i.e. nitrogen and carbon rich material. Brown materials are usually dry and include eggshells, sawdust and wood shavings, dry leaves, etc. Brown materials are slow to decompose and are rich in carbon. Green materials are usually moist and include green leaves, grass cuttings, vegetable and fruit peelings, tea bags and flowers. Green materials act as natural activator and help to speed up the composting process.

 A good mix of brown and greens achieves the best balance and helps with aeration and amount of water in the pile. Too much of one or the other and you won’t make a good compost. For best results, place the ‘greens’ and ‘browns’ in alternate layers about ten inches thick. It is important to get the mix right – usually 1/3 of nitrogen (green) material and 2/3 carbon (brown) material gives the best results.

The finished product

The brown/green mix previously mentioned usually gives the best results. But as with most things, getting the correct mix comes with experience! When compost is ready to use you will not be able to recognize any of the original ingredients.

It should be dark brown/black and feel like topsoil in your own garden. To harvest your finished compost, simply open the lid at the base of the compost bin and shovel it out. Replace the lid when you are finished. Use your compost as mulch around plants, as a top dressing over your lawn to fertilize the soil or as a soil improver in vegetable or flower beds.

References

Cornell Waste Management Institute (2005). Home Composting. Department of Crop and Soil Sciences. 4pp. This brocure is available on our Small Scale or Backyard Composting site: http://cwmi.css.cornell.edu/smallscale.htm.

De Koff, J. P.; Lee, B. D.; Mickelbart, M. V. (2007) Household Composting: Methods and Uses for Compost. Home & Environment. 5pp.

Coservation Agriculture in Mozambique

Conservation agriculture

The conventional agriculture makes the use of agricultural inputs for food production. In these systems the soil is seen as substrate that guarantees physical support, water and nutrients for the plants. The role of the farmer is centered in satisfying all the needs of plants with external inputs (fertilizers to provide nutrients, pesticides to protect the plants and water). Some of these practices are needed in specific conditions and with appropriate planning and management. However, some of these practices can cause serious problems to the human being and environment (eg.: loss of soil fertility and reduction in yield, erosion, increase in the drought and flood risks, contamination of surface and underground water, contamination and soil degradation, etc.) (FAO, 2001).

The principle of Conservation Agriculture (CA)

Conservation agriculture (CA) emerges as an alternative solution to minimize the negative effects of conventional agriculture. The principle of conservation agriculture is to maintain and increase yields of crops that are resilient against droughts and other risks while at the same time guarantee the protection and stimulate the biological functions of the soil. Thus, the two important aspects in the implementation of CA are zero tillage and the maintenance of crop cover (green or dry vegetal material) in the soil surface. Generally, the crops are sown (or planted) in this cover system with special equipment. However, though the zero is an essential aspect of CA its isolated use does not qualify in the principles of CA tillage if the farmer is not practicing crop rotation and does not keep a permanent soil cover he is not practicing CA. The soil cover also contributes for the inhibition of germination of weed seeds minimizing therefore the competition of weeds with the main crops. Swanson and Jacobson (1956) observed that in irrigated crops with adequate fertilization there is a reduction on weeding as a consequence of increase in crop cover which also improves the soil strucuture and increase production and productivity of the crop.

     

 Conservation Agriculture in Mozambique

In Mozambique under the rainfed cropping systems where small scale farmers suffer due reduction in soil fertility and water dynamics in the soil, the recovery of organic matter of the soil is essential for the stabilization of crop production. However, in tropical conditions, the processes of degradation of organic matter are accelerated and do not guarantee the improvement of soil properties at long term. As such, in order to create a soil environment with stable organic matter there is a need to initially add organic matter to the soil (feed the soil microorganisms) and avoid chemical and mechanical impacts on the soil. For example, FAO (2001) demonstrated that with surface tillage or not tilling the soil and addition of crop residues it is possible to increase the activities of warms as compared with areas where there is deep tillage. Therefore, providing a permanent soil cover (or semi-permanent) through growing crops, crop residues or mulch, guarantee food for soil microorganisms, protect against erosion (by rainfall or wind), improves water infiltration, reduces the loss of soil moisture and regulates soil micro fauna. A study conducted by Botha (2013), observed higher gains in the productivity of maize when conservation agriculture was used. Apart from that there were more infiltration rates in conservation agriculture system.

In Mozambique the conservation agriculture is a key tool to boost agricultural productivity and contribute to poverty reduction (solution of problems such as delayed onset of rainfall, low use of inputs, etc). However, for a complete adoption by farmers there is a need to undertake basic agronomic studies in the different agro ecological zones especially on the rates of fertilizers, crop rotation and weed control. In addition there is a need for scientific studies that compare CA with conventional agriculture in different agro ecological zones and farming systems of crops as indicated by Grabowski et al. (2013), Mouzinho et al. (2013) and Grabowski and Mouzinho (2013).

According to Grabowski et al. (2013), emphasis is put on the role of research in the socio economic context in order to evaluate the chemical and non chemical methods of control of weeds. While the chemical control of weeds can be effective, the lack of herbicides in many parts of the country justify the need of studying other methods of weed control. Apart from that, according to the same authors there is a need to undertake studies to better understand the decisions from the farmers with respect to the profitability and risk of CA as related to conventional agriculture including the analysis on changes in occupation and the impact on gender. The aspects raised above deserve also the participation of rural extension that will be responsible for the dissemination of the generated information to the farmers.

References

Grabowski, P.; Walker, F.; Haggblade, S.; Maria, R.; Eash, N. (2013). Conservation Agriculture in Mozambique – Literature Review and Research Gaps. Working Paper No 4E. Directorate of Training, Documentation, and Technology Transfer. IIAM.27pp.

Macias – Vazquez, F.; Arbestain, M. C. (2002). Alternativas para el Secuestro de Carbono en Suelos y Biomasa: Aprendiendo de la Naturaleza, Aprendiendo de los Suelos. Departamento de Edafologia y  Química Agrícola. 32pp.

Malavolta, E. (2006). Manual de Nutrição de Plantas. Centro de Energia Nuclear na Agricultor. 631pp.

Masangano, C.; Mthinda, C. (2012). Pluralistic Extension System in Malawi. International Food Policy Research Institute (IFPRI). 68pp.

Methods of Evaluating Structural Policies (MEANS). (1999). Evaluating Socio-Economic Programmes, Selection and Use of Indicators For Monitoring and Evaluating. Volume 2. European Comission. 245pp.

Mouzinho, B.; Cunguara, B. e Donovan, C. (2013). Uso de Agricultura de Conservação pelos Pequenos Produtores no Centro e Norte de Moçambique, 2010/11. Flash Nº 67P. Resultados de Pesquisa da Direcção de Economia, Ministério da Agricultura.5pp.

Mutambatsere, Emelly. (2006). Trade Policy Reforms in the Cereals Sector of the SADC Region: Implications on Food Security. PhD Candidate, Cornell University Applied Economics and Management; Australia; 16pp.

Porta, J., Lopez-Acevedo, M., Roqueiro, C. (1999). Edafología para la Agricultura y el Medio Ambiente. 2ª Edición. Mundi-Prensa. 848pp.

Prochnow, L. I.; Casarin, V.; Stipp, S. R. (2010). Boas Praticas para uso Eficiente de Fertilizantes. IPNI. Vol 2 – Nutrientes. 362pp

Rafael, R.B.A.; Fernandez-Marcos, M.L.; Macias-Vazquez, F. (2012). Caracterização Química e Mineralógica de uma Rocha Fosfórica e seu Potencial Fertilizante em Diferentes tipos de solos. Tese para obtenção de grau de mestrado em Meio Ambiente e Recursos Naturais. Departamento de Edafologia e Química Agricola-USC.109pp.

Raij, V. (2011). Fertilidade do solo e Maneio de Nutrientes. Instituto Agronómico de Campinas. Piracicaba – Brasil. 420pp.

Inorganic fertilizer on crop grow

Introduction

The increase in population and the need for cultivating the same amount of land year after year lead to the reduction in soil nutrients that are removed by plants and the reduction of soil fertility as a consequence. In the classic form we define soil fertility as the capacity of the soil to satisfy the nutritional needs of plants in quantities and adequate proportions (Porta et al., 2010; Malavolta, 2006; van Raij, 2011; IPNI, 2010).

Importance of inorganic fertilizer for crop grow

Many countries in tropical and subtropical zones of Africa and Mozambique in particular have old soils. These are poor soils in terms of nutrients, rich in residual elements (poorly soluble), acidic of low fertility (Chesworth, 1992; Macias-Vazquez, 2002). The technologies for fertilizer use are fundamental to make these soils productive and in turn increase agricultural productivity. These soils will be productive only with fertilizer application in a sustainable manner, use of integrated soil fertility management techniques, conservation agriculture, use of organic fertilizers and green manure, recycling of residues with potential for fertilizer always accompanied with good agricultural practices (crop rotation intercropping crop cover or mulching). 

Fertilizer is any natural or synthetic substance that contains one or more recognized nutrients applied in the soil or on a plant that is meant to promote the growth of the plant. This can be organic (biofertilizer), inorganic combined, etc. The inorganic or mineral is produced through a chemical process and/or derived from an inorganic or synthetic substance. On the other hand corrective is an inorganic compost composed of calcium carbonate (or magnesium) or sulfur used to neutralize the acidity (and supply calcium and magnesium to the plants) or alkalinity of the soil respectively (Regulations for Fertilizer Management, 2013). 

The technology for the use of mineral fertilizers is essential and more adequate for the increase of agricultural production and productivity. Long time ago, some farmers were frustrated with use of fertilizers as the recommendations on fertilizers were not adapted enough to their specific conditions (Fairhurst, 2012). Several studies revealed that the use of fertilizers (and correctives), improved seed and irrigation can result in significant gains on yields. It has also been demonstrated that fertilizers have the potential as powerful tool to increase productivity in Sub-Saharan Africa. On the other hand, the agronomic and ecological aspects of fertilizer use can be eliminated through the combination of use with organic inputs (ex.: compost, organic fertilizers, green manure, etc.) and the locally available resources such as phosphoric and calcareous rocks. The inorganic fertilizers can be categorized in terms of their content of essential nutrients. The essential or macronutrients (N, P, K, Ca, Mg, S) or micronutrients (Fe, Cu, Mn, Zn, etc.) can be supplied to the plant through the use of fertilizers.