Management of surface cracks in black Vertisols (Typic chromusterts) by soil amendments and land uses in Chambal region, India

Soil cracks provide an opportunity for water recharge during rainy season thereby reducing risks of soil erosion and increasing soil moisture reserve in the semi-arid regions. Despite their importance, scientific knowledge on managing cracks in Vertisols in India is scanty. Thus, the objective of this study was to quantify effect of different soil amendments i.e., wheat-straw (SJ, farm yard manure or FYM (S₂), saw-dust (S₃), gypsum (S₄), and flyash (S₅) on cracks formation in a Vertisols. Initially, an incubation study was conducted with four levels i.e., 0, 2.5, 5.0 and 10 gkg"¹ of each amendment. Results indicated that use of wheat straw caused the least crack volume followed by that with FYM, sawdust, gypsum and flyash. Increased rate of application of soil amendments had significant effect on reduction of the crack volume. A follow-up field experiment was conducted under three different land uses i.e., cropland [intercropping of sorghum {Sorghum biocolor L.) + pigeon pea (Cq/anwi¹cajan L.) at 1: 1 ratio], grassland (dhaman grass-Cenchrus ciliaris L), fallow land (cultivated fallow) with two levels i.e., 10 Mg ha'and 20 Mg ha"¹ of soil amendments. The least crack volume was observed with wheat straw followed by that with sawdust, FYM, fly ash, and gypsum. Increasing the rate of application significantly reduced the crack volume. Further, a significant negative correlation (R²= 0.62, P< 0.01) was observed between soil moisture content and the crack volume. Crop yields significantly increased with the addition of different soil amendments by as much as 38% over that of the control. However, the yield of grass was not affected by these amendments.