Investigations on effectiveness of wheat and rice straw mulches on moisture retention in potato crop (Solanum tuberosum L.)

Mulching is a practice recommended for soil moisture conservation in potato. The wheat straw and rice straw obtained as major crop residues were used as mulching materials to compare their effectiveness for soil moisture retention in potato crop.

The field experiments were conducted in a randomized complete block design replicated thrice with three treatments viz. plots incorporated with wheat straw mulch, rice straw mulch at the rate of 10 tonnes per hectare each and no mulch serving as control. The soil moisture was determined using a soil moisture probe and data were recorded daily at 10 cm, 20 cm and 30 cm soil depths. The Field Emission Scanning Electron Microscopy was used to investigate moisture retention characteristics of the mulch materials.

Soil moisture retention varied as wheat straw mulch > rice straw mulch > no mulch at 10 cm, 20 cm and 30 cm soil depths, respectively. Highest moisture retention in wheat straw mulch at 10 cm depth is attributed to better moisture absorption ability of wheat straw in comparison to rice straw. Field Emission Scanning Electron Microscope images indicated the presence of smaller sized micro tubes in wheat straw than rice straw, which resulted in more water retention, thereby substantiating the findings of the study.

Wheat straw mulch is more effective than rice straw mulch for shallow rooted crops like potato, due to better moisture absorption and retention in upper soil layer.