New tech promises to kill weeds in rice and wheat fields, remove need for stubble-burning

New tech promises to kill weeds in rice and wheat fields, remove need for stubble-burning

Subject: Environment

Sec: Agriculture

Context:

A push for direct-seeded rice and zero-tillage wheat, using a new non-GM herbicide-tolerance technology, has the potential to reduce the environmental footprint of India’s two major cereal crops.

More on News:

• Cultivating rice using less water and not burning the leftover straw after harvesting, and wheat without any ploughing and land preparation, has been a holy grail for agricultural scientists and policymakers concerned over the ecological footprint of the two cereal grain crops.
• The breeding of varieties/hybrids that can “tolerate” the application of a herbicide – Imazethapyr – to control weeds and grasses that affect the growth of crop plants by competing with them for nutrients, water and sunlight.

Kharif season:

• The kharif season has seen the commercial planting of two basmati varieties (Pusa Basmati 1979 and Pusa Basmati 1985) and two non-basmati rice hybrids (Sava 134 and Sava 127), developed by the Indian Agricultural Research Institute (IARI) and Savannah Seeds Pvt. Ltd respectively.
• These contain a mutated acetolactate synthase (ALS) gene that enables farmers to spray Imazethapyr for controlling weeds in rice, such as Echinochloa colona (commonly called jangli chawal), Cyperus rotundus (motha) and Trianthema portulacastrum (patthar-chatta).

Rabi season:

• In the rabi (spring-winter) season, Mahyco Pvt. Ltd is expected to launch its wheat varieties, Goal and Mukut, which are also amenable to Imazethapyr application for controlling Phalaris minor (gulli danda), Chenopodium album (bathua) and other such major weeds.
• The Jalna (Maharastra) based company and Savannah Seeds – the South Asian subsidiary of the Alvin (Texas)-headquartered RiceTec Inc. – have even formed a joint venture to take their Imazethapyr-tolerant ‘FullPage’ direct seeded rice (DSR) and ‘FreeHit’ zero-tillage (ZT) wheat technologies to farmers for making this cropping system “more climate-smart and sustainable”.

Herbicide-tolerant solutions

• DSR and ZT wheat basically replace water and repeated field ploughings with a chemical herbicide (Imazethapyr) to take care of weeds.
• DSR dispenses with the need for any paddy nursery, puddling, transplanting and flooding of fields.
• ‘FreeHit’ ZT technology makes it possible to sow wheat directly – without any paddy stubble burning or even land preparation.
• Imazethapyr is to be sprayed along with Metribuzin, a selective herbicide already used in wheat, when the crop is about 25 days old.

Direct Seeded Rice (DSR)

The DSR method involves sowing rice seeds directly into the field rather than transplanting seedlings. This approach has several advantages, including:

• Reduced Water Usage: DSR requires significantly less water compared to traditional transplanting methods. While conventional puddling methods necessitate around 15 irrigations, DSR can reduce this to about 10 irrigations, leading to water conservation.
• Lower Labor Costs: The DSR method reduces labor requirements associated with transplanting, making it a more cost-effective option for farmers.
• Mitigation of Greenhouse Gas Emissions: By minimizing the need for puddling, DSR helps lower methane emissions, contributing to a more sustainable agricultural practice.

Zero-Tillage Wheat

Zero-tillage (ZT) cultivation involves sowing wheat directly into the stubble of the previous crop without ploughing the field. This method offers several benefits:

• Soil Health Preservation: ZT helps maintain soil structure and reduces erosion, promoting long-term soil health.
• Time and Cost Efficiency: Farmers can save time and costs associated with land preparation, as ZT eliminates the need for ploughing and reduces fuel consumption.
• Stubble Management: The approach addresses the issue of stubble burning, a prevalent practice that contributes to air pollution. By incorporating stubble into the soil, ZT promotes nutrient cycling and enhances soil fertility.