After reading this article you will learn about the Puddling of Soil:- 1. Meaning of Puddling 2. Advantages of Puddling 3. Disadvantages.
Meaning of Puddling:
Puddling of some heavy-textured soils leads to an increase in total soil volume and a decrease in bulk density. This is due to the destruction of aggregates and the corresponding loss of inter-aggregate. Those soils in which the clay fraction disperses when the soil is worked wet, form a random gel-like structure of the soil particles.
The micro-aggregates are ‘destabilized’ by the puddling. As water dries up, the soft puddle soil will tend to ‘harden’. Puddling cause partial dispersion of clay particles, which releases sufficient clay to fill many of the pores between the structural units, will be sufficient to create a characteristically ‘puddled’ structure.
The soil surface layer is made dense and compact. Eventually, the porosity of this surface layer is reduced by the infiltration of muddy surface materials. Then the important entrance channels to deep soil are closed. The soil-profile material can no longer absorb air freely.
Wet system of rice cultivation needs puddled condition, which involves ploughing of land in moist condition. The lands are ploughed and re-ploughed, with planking after each ploughing, to bring the soil to a fine ‘puddle’ condition. The whole of the upper layer of the soil should be in this smooth soft muddy condition, permitting the roots to ramify freely in the medium without being obstructed by hard layers.
In the puddled soil, water is retained in the field. For rice crop, it is important to maintain standing water in the field as rice is semi-aquatic crop. Puddling helps in the retention of water, so that rice can be grown successfully on puddled soil.
Advantages of Puddling:
1. Less power required in tillage.
2. Easy in transplanting rice due to soft mud. Plants are pushed into the mud with thumb and forefinger.
3. Weeds are controlled by puddling. Buried weeds in the mud do not come out easily.
4. Loss of water by percolation is reduced because of structure less soil and the formation of tillage pan.
5. Increase in availability of nutrients, especially phosphorus, iron and manganese.
Disadvantages of Puddling:
1. A large quantity of water is required for puddling the soil.
2. Soil structure is destroyed.
3. In paddy field, other upland crops may not grow well due to structure less soil and presence of tillage pan.
4. Because of absence of air in the paddy field, toxic substances like hydrogen sulphide, ferrous oxide etc., are formed.
5. Loss of nitrogen (de-nitrification) is also occurred in water- logged paddy field.
6. Root development is poor.