Bio‐tillage improves soil physical properties and maize growth in a compacted Vertisol by cover crops

Abstract For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.

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Effects of the combined application of biomaterial amendments and polyacrylamide on soil water and maize growth under deficit irrigation

Canadian Journal of Soil Science ◽

10.1139/cjss-2018-0091 ◽

2019 ◽

Vol 99 (2) ◽

pp. 182-194

Author(s):

Yajin Hu ◽

Nini Guo ◽

Robert L. Hill ◽

Shufang Wu ◽

Qin’ge Dong ◽

...

Keyword(s):

Physical Properties ◽

Soil Water ◽

Deficit Irrigation ◽

Irrigation Management ◽

Field Capacity ◽

Soil Physical Properties ◽

Soil Conditions ◽

Irrigation Level ◽

Maize Growth ◽

Irrigation Levels

Combined applications of mixed biomaterial amendments and polyacrylamide (MBAP) to maize in semiarid areas have the potential to improve soil physical properties such that improved crop performance may be obtained under deficient irrigation management. In this study, three MBAP applications were C0 (conventional N fertilization application) and C2 and C4 (MBAP applied at rates of 2 and 4 t ha−1, respectively); three irrigation levels were W3 (nearly full irrigation, 85%–100% of field capacity), W2 (light deficit irrigation, 65%–75% of field capacity), and W1 (medium deficit irrigation, 55%–65% of field capacity). Under the same irrigation level, the MBAP significantly decreased soil bulk densities and increased soil hydraulic conductivities and soil water contents. The effects of irrigation levels on soil bulk densities and soil saturated hydraulic conductivities were not significant. Consequently, MBAP improved soil conditions for maize growth and increased grain and biomass yields, especially at the two deficit irrigation levels. Compared with that of C0, grain yields for C2 and C4 were increased by 52.8% and 39.3% under W2, and by 23.5% and 13.7% under W1, respectively. The MBAP and irrigation had significant interaction effects on evapotranspiration during sowing to jointing and on plant heights at 32 d after sowing. The incorporation of MBAP (2 t ha−1) and chemical fertilizer (111.8 kg N ha−1) resulted in the greatest yields under light deficit irrigation and seemed the best approach to improve soil physical properties and sustain maize productivity using limited water resources in dryland regions.

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