Effects of cropping and puddling practices on the cracking patterns in paddy fields

Effects of rice straw incorporation and tillage depth on soil puddlability and mechanical properties during rice growth period

“…This work suggests that soil puddlability impacts on shrinkage capacity (Deng et al, 2014). The change in soil structure can cause rapid changes in soil strength and hydraulic properties (Ringrose-Voase et al, 2000;Yoshida and Adachi, 2001;Kukal and Aggarwal, 2003a;Mohanty et al, 2004;Mousavi et al, 2009) and then impact rice and post-rice crop yields (Kirchhof et al, 2000;Kukal and Aggarwal, 2003b;Mohanty et al, 2004;Lennartz et al, 2009). However, it is unclear how puddlability affected by SOC concentration will further influence soil mechanical and hydraulic properties and then root growth during the rice growth period.…”

“…After puddling, the muddy suspension over the plough pan becomes consolidated, with micro-cracks formed due to repeated cycles of wetting and drying during the rice growth period (Yoshida and Adachi, 2001;Timsina and Connor, 2001). Soil shrinkage and swelling due to wetting and drying cycles is a key process controlling the formation of soil structure in paddy field.…”

Numerical analysis of crack generation in saturated deformable soil under row-planted vegetation

“…Although the model assumes that the absorption of water occurs only at the side boundaries, the roots extend to the inter-row space, absorbing water everywhere. According to Yoshida and Adachi (2001b), the percentages of rice roots at 10, 20, and 30 cm from the rows are 70%, 30%, and 10% of that under the row, respectively. Assuming the amount of absorbed water is proportional to the density of roots, 70% of water is absorbed within 10 cm from the rows.…”

“…When the crops are immature, the flux is small; however, the cracks are not necessarily formed at the center of rows because soil evaporation and/or other factors are relatively substantial. The inter-row crack formation without any transpiration is dominated by the distribution of the soil's mechanical strength against the tensile stress (Yoshida and Adachi, 2001b). Soil reinforcement by roots or the tracks of agricultural vehicles are among the important determinants of the formation of crack geometry in this situation.…”

Impacts of long-term chemical and organic fertilization on soil puddlability in subtropical China

“…One of the most dramatic forms of soil structure changes is puddling tillage in rice fields. Puddling tillage involves several rounds of agitating soil under the submerged condition, aiming to soften and flatten the surface soil to ease transplanting of rice seedlings, to control weeds, to mix fertilizers and crop residues into soil and to reduce water leakage (Sharma and De Datta, 1985;Yoshida and Adachi, 2001). Intensive puddling in water disperses soil into microaggregates and primary particles (Chen et al, 1984) and destroys soil macropores (Eickhorst and Tippkotter, 2009), which benefits rice crop transplantation and establishment.…”