Water plays an essential part in the entire growth cycle of the rice plant. Water ensures the healthy growth and eventually a bountiful harvest of the crop. In addition, water also plays another equally important function in ensuring that the paddy field is free of weeds.

The construction of the Muda and Pedu Dams to conserve water resources and the network of canals and drains has enabled double cropping in the entire Muda Scheme of 96,588 hectares in Kedah and Perlis. The Muda Scheme, aptly named the Rice Bowl of Malaysia, now produces about 40 % of all the rice in Peninsular Malaysia.
Rice cultivation practices have changed since the scheme was established.

Transplanting

Until the early eighties, transplanting was the main method to establish the crop. Here rice seedlings are raised in small nursery plots and later transplanted by hand to the main field. In this labour-intensive method water is retained in the fields. Since weed seeds cannot germinate under flooded conditions, weeds are not a major problem in the fields.

However, Malaysia’s rapid industrialisation in the eighties meant a massive out-migration of farm workers and this created a critical labour shortage. Rice farmers had to adopt mechanisation and employ other labour-saving techniques to replace the traditional labour- intensive ways. As a result, direct seeding rice culture took over as the crop establishment technique in the Muda Scheme.

Wet Direct Seeding

Wet direct seeding is now practised by the nearly all farmers in the MADA area. Wet seeding requires the rice field be levelled, ploughed and puddled under flooded conditions. Water is led into the fields for pre-saturation of soils and to soften the soils for ploughing and subsequently seeding. However, just before seeding water has to be drained off again because rice seeds, like all other seeds, require oxygen for germination and growth. Only when the rice seeds have germinated and the young plants established themselves is water re-introduced in the field.

Wet direct seeding therefore not only uses more water, but also loses a fair amount of soils when the water is drained from the field. This pollutes the waterways and rivers. In addition, the exposed rice fields enable weed seeds to germinate. Grassy weeds infestation is a serious problem arising out of this change from transplanting to direct seeding. Direct seeded rice crop therefore requires heavy usage of herbicides to control the grassy weeds, thus increasing costs and aggravating the water pollution problem.

More recently, direct seeding has caused the emergence of a new type of rice called weedy rice or padi angin which is early maturing and easy shattering. The origin of this new type of rice is still not completely known but it has become a major factor of yield loss in Malaysia and some neighbouring rice producing countries. As the name suggests, padi angin perpetuates and establishes itself very quickly in the rice field because the early ripened grains are shattered and blown by wind to the field. Once the padi angin is established in the fields, they are very difficult to eradicate as they cannot be killed by herbicides (they belong to the same genus and same species as rice). It is a big problem because they compete with the normal rice for fertiliser and farmers cannot harvest their grains!

Water Seeding

Recently a new innovative rice crop establishment method called water seeding has been developed to overcome the grassy weeds and paddy angin problem in the MADA area. With this method the seeds are first soaked in water with chemicals (mainly peroxide-based compounds) that will supply enough oxygen to enable the seeds to germinate in a flooded field.

There are many advantages of this new technique. Firstly, water introduced for pre-saturation of the field and for subsequent ploughings is retained in the field during seeding, thus saving vital water resources and reducing pollution to the waterways.

Secondly, standing water in rice field will prevent the germination of weeds and padi angin seeds, thus reducing the infestation of these two groups of unwanted plants. Water seeding technique has high potential in saving water and costs of production.

Demonstration Project

Realising the importance of this water seeding crop establishment technique, MADA has initiated a demonstration project with the support of the IRBM project to fine-tune the technique in their Research and Training Centre in Alor Serdang, Kota Sarang Semut, Kedah. Initially, MADA is seeking the optimum water level for good crop establishment and determining the required water consumption.

Data from the first trial in season 1/2005 are very encouraging - both in terms of water saving and in control of grassy weeds and padi angin. Once this method is proven to be practical and effective, MADA will continue to search for more answers to field problems that may arise out this new water saving technique. Wide adoption of this technique will not only benefit farmers but will also contribute towards the conservation of the precious water resources.