Organic agriculture

To mitigate climate change :

Dr N Yogaratnam

There is dramatic evidence that various Greenhouse Gases are responsible for global warming and climate change. It is also clear that the most important solution to global warming is the dramatic reduction of fossil fuel use, and that other strategies shall not be an excuse to continue with business as usual

The role of agriculture

Agriculture is a major contributor to emissions of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2). On a global scale, agricultural land use in the 1990s has been responsible for approximately 15 percent of all GHG emissions.

One third of all carbon dioxide emissions come from changes in land use (forest clearing, shifting cultivation and intensification of agriculture). Around two thirds of methane and most of nitrous oxide emissions originate from agriculture.

At the same time, agriculture offers options to reduce GHG significantly. One is to reduce emissions and, thereby, to minimise the production of atmospheric CO2, CH4 and N2O. Agriculture shares this emission reduction potential with industry and other sectors. The second option consists in systematically sequestering carbon dioxide in soils and in plant biomass. It is unique for all types of land use.

However, the potential contribution of the land use sector for climate protection is limited. Although sinks in vegetation and soils have a high potential to mitigate increases of CO2 in the atmosphere, they are not sufficient to compensate for heavy inputs from fossil fuel burning. The long-term solution lies in a reduction of the use of fossil fuel (developing alternatives to fossil fuel and reduce energy consumption.

Yet the contribution from the land use sector could buy time during which alternatives to fossil fuel can take affect.

But mainstream agriculture is moving in an opposite direction; increasing releases of GHG from the green sector have made agriculture a producer of global warming rather than a mitigating factor.

Emission reduction

Organic Agriculture can significantly reduce carbon dioxide emissions. As a viable alternative to shifting cultivation, it offers permanent cropping systems with sustained productivity.

For intensive agricultural systems, it uses significantly less fossil fuel in comparison to conventional agriculture. This is mainly due to the following factors,

* Soil fertility is maintained mainly through farm internal inputs (organic manures, legume production and wide crop rotations),

* Energy-demanding synthetic fertilizers and plant protection agents are rejected, and,

* External animal feeds - often with thousands of transportation miles - are limited to a low level.

As a consequence, the organic variants have in most cases a more favourable energy balance. Nevertheless there are reasons for organic farmers to do more to further reduce their dependency on fossil fuel and there are reasons to pay attention to the energy use on the food distribution system.

In avoiding methane, Organic Agriculture has an important though not always superior impact on reduction.

Through the promotion of aerobic micro-organisms and high biological activity in soils, the oxidation of methane can be increased. Secondly, changes in ruminant diet can reduce methane production considerably.

However, technology research on methane reduction in paddy fields - an important source of methane production - is still in its infancy.

Nitrous oxides are mainly due to overdoses and losses on nitrogen. These are effectively minimized in Organic Agriculture because:

* No synthetic nitrogen fertilizer is used, which clearly limits the total nitrogen amount and reduces emissions caused during the energy demanding process of fertilizer synthesis.

* Agricultural production in tight nutrient cycles aims to minimize losses.

* Animal stocking rates are limited. These are linked to the available land area and thus excessive production and application of animal manure is avoided.

* Dairy diets are lower in protein and higher in fibre, resulting in lower emission values.

Using biomass as a substitute for fossil fuel represents another emission reduction option. Organic Agriculture is well positioned in this sector.

It has the advantage that application of inorganic N-fertilizers are avoided, which otherwise would cause significant emissions of N2O and use a lot of energy.

Sequestration potential

Organic Agriculture has a particular sequestration potential as it follows the key principle of tight nutrient and energy cycles through organic matter management in soils.

This is achieved through improved practices in cropland management and in agroforestry.

Various long-term trials provide evidence that the regular addition of organic materials to the soil is the only way to maintain or even increase soil organic carbon (SOC).

The systematic development and application of organic fertilization technologies has been the domain of Organic Agriculture for many decades and outstanding results have been achieved so far. Key issues of technology development have been:

* To optimise the quantity and application of organic manure. A close integration of crop production and animal husbandry and the systematic recycling of organic waste are basic elements.

* To improve organic waste processing techniques to obtain high quality manure. Through composting of animal and plant residues losses in the humification process are minimized and a higher proportion of the solid humus fraction is achieved.

Long and diversified crop rotations and legume cropping are further characteristics of Organic Agriculture that help to increase SOC.

In conventional agriculture, conservation tillage is largely promoted as a measure to sequester carbon dioxide.

This technology combines minimum tillage with organic covers, herbicides and often herbicide resistant GMO crops.

Both of the last two are prohibited in organic agriculture. Latest research results revealed that gains in soil organic carbon have been overestimated and are partly or completely offset by increased N2O emissions.

Thus it can be concluded that minimum tillage combined with mineral fertilizer application compares less well with Organic Agriculture if the focus is on GHGs in general rather than considering carbon sequestration alone. The task of Organic Agriculture will be to integrate conservation tillage in a way that negative effects are avoided.

Agroforesty - a management system that integrates trees in the agricultural landscape - is another technology that is systematically applied in Organic Agriculture. It is a feasible method to succeed shifting cultivation systems but also to improve and add value to low productive cropland.

Agroforestry holds the biggest potential of agricultural carbon sequestration in tropical countries.

It is worth noting that the sequestration of carbon, i.e., an increase of soil organic matter is also leading to more fertile soils, better water retention capacity and reduced nutrient leakage.

A strategy for climate protection

Several the measures mentioned above are often referred to as "recommended management practices." Any type of agriculture could use them, but Organic Agriculture is unique in the sense that it offers a strategy that systematically integrates most of them in a farming system.

This strategy comprises compulsory standards superior in their impact on climate protection. It also comprises a well functioning mechanism of inspection and certification that guarantees compliance of the organic principles and standards. The strictness of the system has made Organic Agriculture accountable and a generator for innovation.

Waste into wealth

The basic requirement in organic farming is to enrich the biomass to increase the nutrient value from 0.3 to 0.4 per cent to one to two per cent. There are technologies now available to enrich the biomass, including Farm Yard Manure three to four times if properly composted.

Several million tonnes of agricultural waste is available in the country every year, but most if it is not properly used. We must convert our 'filth into wealth' by mobilizing all the biomass in rural and urban areas into bioenergy to supply required nutrients to our starved soil and fuel to farmers.

Several options are available to increase the biomass to meet the requirement of minimum plant nutrients. A portion of the cropping land could be made available for growing green manure along with the regular crop. This green manure can be harvested at the right time and composted, stored and used in the following growing season.

The land lost in growing green manure would be compensated by increased yield in the remaining area and year after year productivity would remain the same even if it does not increase. Our social forestry can be planned to augment our biomass requirement, in addition to the fodder and fuel now being supplied.

To make several hectares of our starved land productive, adequate organic amendments have to be provided. This requires not only enormous quantities of biomass but also ingenuity and techniques to enrich it to supply the required quantity of nutrients to the crops. Even if the present production of around 13 million tonnes of fertilizers is increased to around 20 million tonnes by the turn of the century, it might not be available at affordable prices to the farmers.

Unless plant nutrients are supplemented adequately with compost and / or bio-fertilizers, sustainability of production cannot be achieved.

Therefore, adequate attention to enriching our soils with as much organic matter as possible is unavoidable.

The thrust and focus on making the thirsty soils sustainable with the maintenance of soil-organic matter and thus supply soil nutrients adequately under tropical conditions, has, however, been elusive.

This must be regarded as a major problem of equal importance as that of soil-moisture availability, and should receive top priority.

Organic carbon content of soil

It is said that most of the organic matter mineralizes four times faster under tropical conditions than in temperate conditions and unless supplemented in every cropping season, the organic carbon content of the soil decreases fast. Most of our soils under the dry-farming system contains less than 0.5 per cent organic carbon. Unless it is raised to 0.9 per cent or one per cent, productivity of the soil cannot be optimized.

Innovations improve economy

Unless the soil is kept covered by some means after harvesting the crop, the top-soil continues to get eroded and productivity decreases. The questions addressed now are, what are the alternatives to prevent the colossal loss of soil nutrients and how to improve soil-fertility for sustainable crop production?

Several new innovations are available to the farmer, including a change of varieties, maintenance of plant population, seed treatment, recommended dose of fertilizer and farmyard manure , plant protection measures, etc. In addition to these interventions, the introduction of new implements and improved breeds of poultry, sheep, piggery and fodder crop are known.

Our soils have been totally deprived of crop residues. The entire crop is harvested and carried out of the field. The straw and stumps are used as fodder and fuel, respectively. Whatever crop residues are left are eaten by termites in most cases.

Some of the experiments carried out under dry-farming conditions have proved the possibility of increasing productivity of the soil by incorporating in it the entire crop residues, at least once in two or three years, taking only the grains. This should be done at a time where there is enough moisture in the soil, which should then be covered completely.

Knowledge on composting

It is doubtful as to how many of our farmers know the value of proper composting, their preservation and application at the right time and right place. Most of our farmers make a compost pit, which is filled every day little by little for over a period of six to nine months. When it rains, it is filled with water, the bottom of the compost becomes cake-like, while the top portion is not compressed well and is semi-dried.

When applied to the fields, it is eaten away by the termites. Most of our composts and farmyard manure have less than 0.5 percent of nitrogen.

If all the crop residues and farmyard manure are properly composted on a flat surface with vats of four to five feet width, four to five feet height and of convenient length, the compost can be enriched to yield one to two per cent nitrogen and other essential micronutrients.

It has to be done in a day, keeping all the materials ready, spreading layer after layer with crop residues and farmyard manure, maintaining at least 60 per cent of the moisture and filling the entire vat at one time. It produces a great deal of heat in the centre.

Therefore, at least once in a month this has to be turned over atleast two to three times, every time adding the required moisture if it is dried.

This process has to be continued for about four to five months. Such compost will have all the ingredients rich enough to provide proper nourishment to the plant.

Most of the FYM or composts taken to the field are either heaped or spread during lean months, much before the planting time. This is a colossal waste, as the compost or the manure loses all its utility unless it is incorporated when there is the right type of moisture in the soil.

The best way to use FYM or compost is in furrows at the time of sowing. Although it is labour-intensive and time-consuming, the reward will be more than expected.

Plantation agriculture

Organic farming is best suited under perennial plantation crops which provide proper shade and cover to the soil, keeping the microbial activity in the soil constant.

However, the cover of the crop itself may not be enough to maintain the soil microbial activity. Unless there is enough organic matter, neither would the applied fertilizer uptake the maximum, nor the continuity of the microbial activity which is suppressed by chemical fertilizers.

Therefore, there is a need to maintain a minimum amount of organic matter through periodical supply. There are instances where higher levels of production of plantation crops like tea, rubber, coffee, cardamom and pepper have been obtained through nutrient ply from organic sources alone.

Incidentally, there is great scope for exporting organically grown tea, coffee, cardamom and pepper. In addition to improving our soil productivity through organic farming, we can look forward to greater demands for our organically grown agricultural produces.

Organic agriculture could contribute significantly to reduce GHG releases and to sequester carbon in soils and biomass. Secondly, there is sufficient evidence that Organic Agriculture is superior to mainstream agriculture.

This is even more important as the capacity of organic agriculture to contribute to the mitigation of climate change can be considered as an ancillary benefit to its primary goal of sustainable land use.

This primary goal is achieved by gains in soil productivity, consecutive food security, biodiversity conservation and many other benefits.

As opposed to the focus of conservation agriculture on a single technology, organic agriculture follows a site-specific and systematic approach that includes a comprehensive set of integrated technologies, because of the inspection and certification systems required in organic.

Strategy for climate protection

In order to include organic agriculture as a strategy for climate protection, two main avenues should be persued;

1. Lobbying initiatives in both public and private sector agriculture and plantation related agencies at national level to make organic Agriculture as explicit part of the agencies GHG inventories; this is an important step to ensure that organic agriculture as a strategy can participate in a joint implement mechanism with public- private sector partnership.

2. A broad initiative, by which organic agriculture projects in different departments and agencies tap into and utilize financial support from various existing carbon funds. Such an initiative can develop suitable instruments for the assessment of carbon sequestration and for the monitoring of project implementation.