US 12,256,659 B1
Spring ploughing and land preparation method through thawing and water puddling for saline-sodic paddy fields and application thereof
Hongyuan Liu, Changchun (CN); Ding Wang, Shenyang (CN); Qingquan Xu, Daqing (CN); Yanhong Zhou, Changchun (CN); and Xintong Liu, Changchun (CN)
Assigned to Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun (CN)
Filed by Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun (CN)
Filed on Oct. 30, 2024, as Appl. No. 18/931,322.
Claims priority of application No. 202410387808.3 (CN), filed on Apr. 1, 2024.
Int. Cl. A01B 79/02 (2006.01)
CPC A01B 79/02 (2013.01) 1 Claim
OG exemplary drawing
 
1. A method for spring ploughing and land preparation with thawed water puddling applied to saline-sodic paddy fields in western Songnen Plain, comprising following steps:
(1) harvesting rice with low stubble left, wherein an average stubble height of the rice is ≤15 cm;
(2) removing straws from fields: removing straws after harvesting from the fields;
(3) ploughing: ploughing at a surface depth of 14-16 cm, breaking soil capillary pores and inhibiting salt return, making a ploughing depth consistent with a depth of a tillage layer in the saline-sodic paddy fields, without causing damage to a deep soil structure; wherein a missing ploughing rate of the ploughing is ≤5%, and a re-ploughing rate is ≤5%;
(4) fertilizing, wherein a time of the fertilizing is in mid to late-March;
(5) irrigating for thawing: from late March to early to mid-April, when a natural thawed depth of a soil layer reaches 6-8 cm, field blocks are irrigated with water and the irrigating is stopped until tops of upturned soils are submerged, and the field blocks are soaked for 1-2 hours; then the upturned soils after shallow ploughing is further thawed through a heat exchange between soil and water, and an overall thawed depth reaches 11-13 cm, with a large number of frozen soil blocks kept at a same time;
(6) carrying out water puddling operation: carrying out the water puddling operation, and a water puddling operation depth is 11-13 cm, consistent with a depth of a thawed layer, wherein a sublayer of the soil is in a frozen state, capable of supporting an operation machinery well; ruts of 2-3 cm in depth are formed at a sublayer of frozen soil by wheel rolling, and a mud layer of 2-3 cm is formed by repeated rolling, matching with a puddling machine of 11-13 cm to form a tillage layer of about 15 cm in depth; and
(7) drying, wherein the drying continues for not less than 20 days, then criss-crossing cracks appear on field surfaces, and a soil in the tillage layer is dried to a depth of not less than 10 cm from a surface downwards.