Cut-soiler based salinity management practices enhancing production of mustard-pearl millet cropping system in India

抄録

Soil salinity is a global issue threatening land productivity, and estimates predict that 50% of all arable land will be impacted by salinity by 2050. Salt affected soils are an important ecological entity in the landscape in most arid and semi-arid regions. In India these soils occupy nearly 6.7 million ha area and represent a serious threat to country’s ability to increase food production to meet the expanding needs. India loses annually 16.84 million ton of farm production valued~₹230.2 billion due to salt affected soils (Mandal et al., 2010; Sharma et al., 2015). The salinity management, especially in arid regions, needs an ‘on farm technology’ solution that can be adopted at individual farm/farmer level. Cut-soiler is a machine developed in Japan that use and manage surface scattered straw material, residue or remaining stems to construct residue filled shallow subsurface channels, while running on the field. The preferential drainage from these channels reduces soil salinity. In this background, Japan International Research Center for Agricultural Sciences (JIRCAS)-ICAR-Central soil salinity research institute (ICAR-CSSRI) collaborative research project is being conducted to evaluate utility of Cut-soiler on salt removal and effect on crop yields in salt affected soils with the use of saline irrigation water. Three saline irrigation water treatments (EC_iw 4, 8, 12 dS m^–1) were applied in two soil types i.e saline and heavy textured. Mustard-pearl millet a major cropping system in hot, arid and saline regions of North West India was evaluated.

Cut-soiler based preferential subsurface drainage reduced 19% salinity in one year of study across the soil types. The saline soil filled plots had higher ECe (5.07 dSm^–1) than the heavy textured non- saline soils (1.39 dSm^–1). The salinity (EC) of 12 dSm^–1 applied irrigation water was significantly (p<.0001) higher (3.6) than 8 dSm^–1 (2.96) that was further higher than 4 dSm^–1 (2.74) applied irrigation water. The study found that saline irrigation water up to 8 dSm^–1 could be used without any additional salt loading. The lower salinity resulted in marginal increase in mustard yield in maiden season and 18.6% increase in pearl millet yield in successive season. Therefore, the Cut-soiler based preferential sub surface drainage may be a possible solution for salt removal from saline soils and preventing salt accumulation with application of saline irrigation water for sustainable crop production in salt affected areas having saline groundwater.