Background

The rice-wheat (RW) rotation provides staple grains for about 20% of the world's population. However, declining yields in long-term experiments, declining factor productivity on farms, and degrading soil and water resources have raised questions about the sustainability of the RW rotation at a time when production must increase at the rate of 2.5% per year to meet projected population growth. In 1992, a consortium was formed between several international agricultural research (CGIAR) centers (initially IRRI and CIMMYT but now also ICRISAT, IWMI and CIP) and the national agricultural research systems (NARS) in Bangladesh, India, Nepal and Pakistan to address these concerns. Cornell joined this consortium in 1995, initially using low levels of funding from the university and then under a US-AID funded Soil Management Collaborative Research Support Program (SM-CRSP) grant ($3 million; September 1996-August 2001). Cornell brought an additional agenda item, namely that the green revolution focus on staple crops has dramatically increased micronutrient (vitamin and mineral) malnutrition in the region. This has happened because cropping systems have been simplified and nutrient rich crops, especially grain legumes, have been displaced. Consequently, our overall program objective is:

Sanctions by the US government against India and Pakistan have largely restricted the program to Bangladesh and Nepal, with small amounts of Cornell funds being used in India and Pakistan. The program is carried out at the district level, using sites selected by the NARS for detailed study (see site map). It has several components:

Diagnosis of soil (and other) constraints on farms and in research experiments in order to establish cause and effect relationships between soil management practices and sustainabilty-productivity indices such as crop yield, crop quality (including nutritional value), soil quality, efficiency of use of inputs (chemicals, water, and labor), and economic viability and social acceptability. This knowledge is used to identify potential soil management interventions.

A key additional component is household/village level studies to characterize socio-economic constraints, household decision making, and analysis of food systems, nutrition and health.

Strategic Research is designed to evaluate innovative soil and cropping systems management practices and to address gaps in knowledge that constrain development of improved soil management technologies. Activities focus on

• tillage and crop establishment practices;

• diversification of the RW cropping system;

• micronutrient enrichment of seeds;

• linkages between agriculture and human nutrition and health.

Technology Adoption activities aim to make better use of existing information and accelerate adoption of improved practices through:

• development and use of geographic information and decision support systems;

• farmer participatory adaptive research and farmer networks to demonstrate

and extend improved practices; and

• workshops aimed at developing linkages among stakeholders and technology

transfer.

Capacity Building of NARS Scientists is being achieved through:

• advanced degree training and scientist exchange opportunities, including

within region activities that utilize the capacities of the stronger NARS;

• training of personnel in specialized and/or state of the art techniques; and

• repair and provision of equipment.

Some Major OUTCOMES AND Accomplishments

Overcoming Soil Constraints to Crop Productivity

• A series of about 40 solarization trials (covering soil with clear plastic to heat to

50C) have led to the following conclusions:

• Soil micronutrient deficiencies have been identified as an important constraint to increased productivity of rice and wheat in Bangladesh and Nepal. These can be overcome by micronutrient enrichment of seed, which has the advantage that difficult to obtain soil analyses are not needed. Current activities are extending seed enrichment to grain legumes and evaluating commercial potential for seed enrichment.
• Soil boron (B) deficiency, fog (which reduces B translocation in plants) and plant genetics have been shown to be interacting causes for sterility in wheat. A third of the lines in Nepal’s wheat breeding program were found to be genetically susceptible to sterility. CIMMYT’s most promising lines for S. Asia and Bangladesh breeding lines are currently being evaluated with the goal of removing susceptible germplasm from breeding programs.
• A mulch of straw has been found to lower floodwater pH in paddy rice and has the potential to increase N use efficiency (which is notoriously poor in rice). This could have a large impact on crop yields in the eastern part of the IGP where farmer use of N fertilizer is sub-optimal.
• In heavy textured soils, deep tillage prior to rice has been shown to benefit wheat productivity without penalizing rice yield. Similarly, direct seeding of rice has given equivalent yields to transplanting and benefits wheat by enabling timely planting.
• The inclusion of grain legumes in the RW rotation is hampered by root diseases, soil micronutrient deficiencies and poor varieties. Current activities are addressing these constraints using a multi-disciplinary approach.

Socio-Economic and Human Nutrition Studies

• Two villages (Jagdal and Haldibari) in NW Bangladesh are the focus of intensive multidisciplinary studies. Initial survey activities characterized agricultural activities and socio-economic factors. Four rounds of a detailed food systems, nutrition and health survey have been completed and data is being analyzed for needs and intervention opportunities. Research projects investigating (i) household decision making tradeoffs between income generation, food security and health outcomes, and (ii) links between soil nutrient status, crop quality and human nutrition and health are underway.
• Economic analysis showed that the high risk of production coupled with government policies that favored mustard and wheat were jointly responsible for the drastic decline in chickpea production in the northwestern Indian States of Haryana, Punjab and Uttar Pradesh.