Combine harvesters are gaining popularity in Pakistan for timely harvesting of wheat. These harvesters are concerned with the grains only and leave high stubbles and machine-ejected straw in the field. Due to non-availability of proper technology, farmers generally burn this left over straw to clear their fields for subsequent crop. This phenomenon has given rise to three major issues:
Introduction
Combine harvesters are gaining popularity in Pakistan for timely harvesting of wheat. These harvesters are concerned with the grains only and leave high stubbles and machine-ejected straw in the field. Due to non-availability of proper technology, farmers generally burn this left over straw to clear their fields for subsequent crop. This phenomenon has given rise to three major issues: environmental pollution associated with fire hazards at farm level; burning of rich soil organic matter; and loss of valuable commodity i.e. finely chopped wheat straw (bhoosa) which is a common cattle-feed and has good market potential. Therefore, a technology which could provide bhoosa to feed their cattle throughout the year and earn a reasonable amount of money through its sale was highly demanded by the farmer.
Technology Development, Demonstration and Recommendation
Keeping in view the farmer’s demand, Farm Machinery Institute, NARC identified and acquired a tractor mounted wheat straw chopper-cum-blower from India through Rice-
Wheat Consortium. The machine was commissioned at FMI workshop and tested at NARC fields during wheat harvest 2001. The results were quite encouraging. Hence, further extensive field testing and demonstrations were conducted at farmer’s fields during wheat harvest 2002. Effective field capacity, field efficiency, fuel consumption, operational cost and bhoosa recovery were ascertained to be 0.8 acre/hr, 60 %, 5-6 liters/hr, Rs. 750/hr and 400-600 kg/hr respectively.
The machine was adapted and commercialized by conducting field demonstrations through local industry. Technical assistance was provided to collaborating manufactures for its indigenization at Daska, Lahore, Gujranwala, Hafizabad, Faisalabad and Multan. Seven manufactures are producing the machine locally and its more than 250 units were in operation during 2006 wheat harvesting season resulting in 4.9 million rupees annual financial benefit to the farming community. Furthermore, the extensive use of straw chopper would help in conserving the natural environment to a considerable extent besides complementing the use of modern combines in Pakistan.
The Technology
Wheat Straw Chopper-cum-blower is a trailed-behind machine both for transport and field operation modes. It harvests the stubbles as well as picks up the combine-ejected straw from the field, chops it into bhoosa and blows it into a trolley hooked at its rear. It can be operated with a greater than 50 hp tractor with 2.2 m width of cut
Key Reference
Zafar, A. W., G. Shahzad and N. Amjad. (2002). Management of straw in combine harvested wheat fields: issue and its solution. Paper presented at National Workshop on Rice-Wheat Cropping System Management, NARC, Islamabad. December 11-12.
