Tillage Practices under INM in Rice

1.0          Objective

After completing this RLO you should be able to:

• describe different tillage practices under INM and their benefits for increased yields of rice.

1.2        Introduction

Tillage is the physical manipulation of soil with tools and implements to result in good tilth for better germination and subsequent growth of rice crop. Tillage is required for seed bed preparation, weed control and soil and water conservation. Improvements in soil structure, soil permeability, soil aeration etc are the main objectives of tillage in rice crop under Integrated Nutrient Management. Proper tillage results in higher infiltration and reduced run-off with increased depth of soil for moisture storage. Summer deep ploughing improves soil structure due to alternate drying and cooling. Organic matter decomposition is hastened resulting in higher nutrient availability.

1.3      Tillage practices under INM in rice

Land leveling

Leveling rice fields improves water use efficiency, increases grain yield, and improves grain quality. Leveling land improves water coverage which:

Ø  Reduces the amount of water required for land preparation

Ø  Improves crop establishment

Ø  Decreases the time to complete tasks

Ø  Results in better crop stands

Ø  Reduces weed problems, and

Ø  Results in uniform crop maturity.

Systems of land leveling

Different systems require different field conditions and operating time.

1. Draft animals and 2-wheel tractors using harrows and leveling boards.

These leveling techniques require total in field water coverage and require 7 to 8 days for a 2-wheeled tractor and 12 days per ha using draft animals.

Land leveling by bullocks under wet cultivation of rice (www.smh.com.au)

 2. Four-wheel tractor using rear mounted tractor blades or drag buckets.

In wet fields a rear-mounted tractor blade is best and in dry fields a hydraulically operated drag bucket is superior. Work rates depend on the tractor size and the amount of soil to be moved. It will take approximately 8 hours to level 1 ha with a rear mounted tractor blade. This reduced to about 4 hours when using a drag bucket.

3.   Four-wheel tractor with a laser controlled bucket.The use of laser controlled equipment results in a much more level field. The objectives of laser land levelling are: to make field more level and smooth soil surface, reduction in time and water required to irrigate the field, more uniform moisture environment for crops, reduced consumption of seeds, fertilizers, chemicals and fuel, and improved field trafficability (for subsequent     operations).