Small Farmers and Resource-Conserving Agriculture: The Prospect of Attaining Environmental Sustainability through Zero Tillage Relay Cropping in Bangladesh

Introduction

Throughout the developing world, as population pressure increases and land holdings shrink, many poor smallholders have resorted to more frequent cropping and intensive agriculture, curtailing traditional long fallows degrading land and reducing production. The U.N.'s Report "The State of Food and Agriculture 2014” states that more than 80 percent of the world's food is still produced by small family farmers, there are more than 500 million family farms manage between 70 and 80 percent of the world's agricultural land; Small and medium sized farms tend to have higher crop yields per hectare than larger operations, the report said as they manage resources and use labor more intensively [http://farmlandgrab.org/24073]. With the spread of Green Revolution technologies an increased production has been achieved, like with cereal yields in East Asia and the Pacific nearly tripling, these modern agriculture technologies are found associated with greenhouse gas emissions, pesticide residues, reduced biodiversity, soil erosion, declining fertility and salt build-ups [1, 2, 3, 4, 5]. As the world’s population tracks towards 9 billion by 2050, increased competition for fixed land and water resources will surely pose problems for maintaining continued productivity increases required to meet food needs. Moreover, with green house gas emission increasing and energy supplies declining, this use of increasing quantities of inorganic nitrogen in modern agriculture presents a serious challenge to sustainability [6].

Bangladesh has managed to accelerate overall GDP growth by one percentage point on average every decade - from 3% in the 1970s to 6% in the last 10 years [7]. Still 73% of about 120 million Bangladeshis live in rural areas and agriculture is the single largest producing sector of the economy comprising about 18.6% (in 2010) of the country's GDP and employing around 45% of the total labor force [7]. Within that, 57% of the agricultural GDP comes from crops, with forestry, fisheries, and livestock making up the remainder. Seventy-five percent of Bangladesh’s cropland is devoted to rice, being the staple food of Bangladesh, rice accounts for 76% of the cultivated area, 78% of the irrigated area, 52% of agricultural GDP, and 71% of caloric intake [8, 9]. During recent decades rice productivity stagnated or even declined in many areas in Bangladesh due to various reasons, intensifying already widespread poverty-related food insecurity, added by the soaring prices of key staples. However, traditionally, many small farmers continue to maintain a sequence in crop rotation growing pulses or oilseeds after rice which are mainly rain-fed. Leguminous pulses recover nutrients consumed by rice earlier, maintaining productivity of land. This strategy of prudently exploiting local inputs and ecological processes rather than using external inputs has particular relevance to future food security in the light of rising food prices and agricultural inputs as well as increasing competition for land, water and energy. For example, the long-term rises in costs of fertilizer-pesticides and irrigation will continue to increase the expenditure of food and making it increasingly unaffordable for the poor. It is smallholders’ low input production system which now feed much of the world’s poor and who will continue to bear much of the world’s future demand for food if remain productive. Also relevant is the fact that struggling small farmers all over the developing world have already been hit hard by climate variability, losing harvests and livestock to drought, floods and struggling to survive amid changing rainfall patterns. Crop productivity is expected to decrease “for even small local temperature increases (1 –2°C)” [10]. According to the IPCC, Bangladesh is slated to lose the largest amount of cultivated land globally due to rising sea levels. A 1m rise in sea levels would inundate 20 percent of the country’s landmass. Within the next 50 years, over 20 million people could be displaced and become “climate change refugees” if sea and salinity levels rise in Bangladesh, according to the government’s 2009 Bangladesh Climate Change Strategy and Action Plan. There is an important need of in depth research and closer scrutiny of what the local communities are thinking about this change, what the small farmers can do as adaptations and possible interventions/future investments needed to deliver sustainable results [4].

Against this backdrop, research suggested that ‘climate-smart agriculture’ , ‘regenerative agriculture’, ‘organic’ or ‘ resource-conserving agriculture’ have sound potential for improving livelihoods of smallholders and contribute to sustainable agricultural production and food security [11, 12, 13]. A recent report asserts that as the human society inevitably face increasingly constrained agricultural resources, these ‘eco-agricultural approaches’ will take on more urgent priority [14]. Resource- conserving agriculture makes the best use of natural goods and services without compromising their future use, and promotes social, environmental and health goals along with productivity gains. Many of these practices are commonly part of traditional agriculture which includes integrated pest and nutrient management, conservation tillage, agro forestry, aquaculture, water harvesting and livestock integration. All these practices/technologies facilitate soil replenishment using locally available organic fertilizers, cover crops, use of nitrogen-fixing legumes, crop rotations, and mulches; zero/reduced tillage, improved water management; and crop diversification to reduce the risk of crop failure. Traditional/resource conserving agriculture does not exclude synthetic agrochemicals if they improve productivity without harming the environment [15]. These alternative systems of agriculture can provide benefits in many different ways: by increasing productivity, by reducing costs, by saving environment from degradation; also when ‘organic’ by increasing product prices. Recent economic crisis resulted in a permanent increase in the cost of fertilizers – by 200% for Zuberi MI, et al. Small Farmers and Resource-Conserving Agriculture: The Prospect of Attaining Environmental Sustainability through Zero Tillage Relay Cropping in Bangladesh. J Agri Res 2018, 3(5): 000171.

nitrogen fertilizers in 2007- suggesting that maintaining or changing to traditional/resource conserving agriculture will result in huge cost savings and also help poor, small farmers to survive and sustain food production in remote areas [16]. Recently, Mica Bennett and Steven Franzel examined 31 documented cases of African and Latin American farmers adopting ‘organic resource conserving agriculture’ and found that yield improved in 19 of the 25 cases that reported on it, food security improved in seven of eight cases, and net income improved in 19 of 23 cases [17]. They observed that successful ‘resource conserving agriculture’ initiatives do not occur spontaneously rather require a variety of skills from smallholders and their allies which include adaptive farm management, effective producer organizations, entrepreneurship, capacity to innovate, value addition and boundary spanning, these being noted in the case of traditional farming in Ethiopia [18].

The majority of small farmers grow, follow ‘resource conserving agriculture’ in that, the rainfed pulses, oil seeds, wheat, spices and vegetables grown during the winter (rabi) after harvesting the rainy season aman rice need minimum external resources. But very often, delayed withdrawal of the monsoon and/or flooding results in late harvest of paddy, thereby also delaying land preparation, sowing of the winter crops like lentil and wheat. Because of the short winter, the delay of every successive day in planting beyond November decreases the growing period and residual soil moisture thus drastically reducing grain yield [19, 20]. Wheat, also a winter (rabi) crop, faces a number of stress factors like short growing season, drought, higher temperature as well as salinity near the coastal areas of Bangladesh (Fig1). Also the farmers here experience very low yield rates due to intensifying salinity stress due to river water decline and sea level rise. No suitable wheat or lentil variety is known for the stressed environment though about 2.8 million hectares of land (one-fifth of the total cultivable land) of Bangladesh is known to be salt affected where only Aman rice can be grown in more salt-affected areas during the monsoon when the salinity decreases due to rain and flood water [21]. Only in low saline areas, after harvesting Aman rice, farmers prepare the land when the soil is ready for winter crops. Often, land preparation needs time and resources, also within a short period the stored moisture in soil becomes inadequate to meet the evapotranspiration (ET) demand of the crop and consequently the crops like wheat undergoes moisture stress of varying intensities [22]. In salinity affected areas supplementary irrigation is difficult and expensive. The district of Satkhira (Figure 1) is one of the South-Western district of Bangladesh which in salinity affected being adjacent to the Bay of Bengal.

Therefore, to avoid delay in planting and reduce the cost of production, farmers need to avoid plowing and land preparation so the prospect of zero tillage and relay cropping or surface seeding in lentil and wheat was explored. Depending on the withdrawal of rain and drying up of land for plowing, no till relay sowing of these crops could be accomplished 15 to 35 days earlier than in conventional tillage and land preparation method. In this study we report two cases how this resource conserving agriculture can contribute to sustainable food production system furthering progress towards food security in Bangladesh with little input.

Materials and Methods

We used to sets of experimental evidences from two research projects with lentil) and wheat carried out for higher degree (Rajshahi University, Bangladesh) [19, 23]. As lentil and wheat are grown during the winter (rabi) season after the harvesting rainy season ‘aman’ paddy (end of October/ early November), often late harvest of the paddy due to late withdrawal of the monsoon or flood water delay drying of soil, preparation of land and sowing all become late. As the winter is short and mild (December to February) in Bangladesh and the residual moisture in the soil dries out rapidly, higher temperature and aridity all affect growth and yield of the crops. Also, traditional plowing and harrowing often result in soil loss due to wind/water erosion.

In the lentil experiment, direct broadcasting of the lentil seeds was done in the paddy field prior to harvest, which avoided the delay due to land preparation in the Agriculture Research Farm, Ishurdi, Pabna, Bangladesh (Figure 1). Two sets of replicated (three) field trials were conducted during the rabi seasons of 2009 and 2010 to test the prospect of lentil relay cropping and to find out the suitable management for better plant establishment and yield. Also the prospect of lentil relay cropping was tested in the farmer’s field of three adjacent Districts in the North-western Bangladesh (Pabna, Natore and Kushtia) in 2010-11 to validate the experimental findings and to create awareness among the farmers.

Zuberi MI, et al. Small Farmers and Resource-Conserving Agriculture: The Prospect of Attaining Environmental Sustainability through Zero Tillage Relay Cropping in Bangladesh. J Agri Res 2018, 3(5): 000171.

Click to enlarge

The upper arrow indicates the lentil experiment sites in Northern region whereas the lower arrow shows the wheat experiment in the Southern. Figure 1: Location of Bangladesh and sites of lentil and wheat experiments.

Lentil seeds were sown in the paddy field on November 1 to 3, 2009 and 2010 in the experimental plots (three replications) and rice was harvested after 7 days keeping the stubbles at about 30 cm height from the ground. The lentil crop was harvested during the first week of March (March, 4, 5 and 6) when about 80% of the lentil plants and pod turned to straw colored. Data collected on yield and related traits from plants of 1 m2 at three locations in a field and seeds and straw yield were converted into kg/ha and t/ha.

The wheat experiment was conducted in the paddy fields of high salinity affected area in the South-eastern coastal belt of Bangladesh in the Shyamnagar sub-district during the winter seasons of 2010 and 2011. The wheat seed (HYV Kanchan) of about 0.5 kg were collected from the authorized dealer from Shyamnagar and were broadcast in the paddy field on November 18, just 18 days before harvesting of the paddy. The stubbles were kept at the height of 15 cm in the field. Electro Conductivity Meter model HI-993310-Hanna, (1344.88) was used to measure electrical conductivity in the more saline and less-saline areas, about 350 gm soil samples from (a) soil surface (b) 13 cm depth and (c) 25 cm depth, were collected between the months of November, 2008 to April 2009.

A paddy field of about 16 x 10 m was selected in Shyamnagar (Figure 2) high salinity affected area, wheat seed were broadcast in the paddy field on November 18, 2009, 18 days before harvesting the paddy. During harvesting the paddy, the stubbles were kept at the height of 15 cm in the field. It is usual practice for wheat growers to give some irrigation and fertilizer for a better yield, but in the present experiment no irrigation and inorganic fertilizers were used. The data collected from the relay crop on individual plant basis from 1 sq m areas of the farmer’s plot for data collection.