Spatio-temporal variation of surface soil hydraulic properties under different tillage and maize-based crop sequences in a Mediterranean area

Aims: The surface crust formed by the drop impact of rainfall and/or irrigation is a prevalent characteristic in many Mediterranean soils. However, the temporal variation of soil hydraulic properties induced by surface crust during the high-frequency irrigation has rarely been investigated. Methods: Beerkan infiltration tests in conjunction with the BEST method were used to investigate the effects of surface crusting on the spatio-temporal variation of saturated soil hydraulic conductivity (Ks, mm s−1), sorptivity (S, mm s−0.5), mean pore size (r, mm), number of effective pores per unit area (N, m−2) in Agramunt, NE Spain. Results: In response to autumn tillage, intensive tillage (IT) increased Ks and S due to higher r and N, but both declined after 60 days. Reduced tillage (RT), maintained comparable Ks and S values, despite having a lower N value. After the spring tillage, both IT and RT developed crusted layers, resulting in decreased Ks, S and N. Long-term no-tillage (NT) showed an increasing trend of Ks and S over time, except for the last sampling. Spatial variation (i.e., between the rows, B-row vs. within the row of crops, W-row) of Ks and S was found, and non-crusted soils (W-row) had consistently higher Ks and S than crusted soils (B-row). Conclusions: Conservation tillage i.e., RT and NT improve the surface soil structure and reduce the risk of crust development. Surface cover by crops may help to prevent crust formation within the row of crops, improving soil hydraulic conductivity

Root hairs improve root penetration, root-soil contact, and phosphorus acquisition in soils of different strength

Root hairs are a key trait for improving the acquisition of phosphorus (P) by plants. However, it is not known whether root hairs provide significant advantage for plant growth under combined soil stresses, particularly under conditions that are known to restrict root hair initiation or elongation (e.g. compacted or high-strength soils). To investigate this, the root growth and P uptake of root hair genotypes of barley, 'Hordeum vulgare' L. (i.e. genotypes with and without root hairs), were assessed under combinations of P deficiency and high soil strength. Genotypes with root hairs were found to have an advantage for root penetration into high-strength layers relative to root hairless genotypes. In P-deficient soils, despite a 20% reduction in root hair length under high-strength conditions, genotypes with root hairs were also found to have an advantage for P uptake. However, in fertilized soils, root hairs conferred an advantage for P uptake in low-strength soil but not in high-strength soil. Improved root-soil contact, coupled with an increased supply of P to the root, may decrease the value of root hairs for P acquisition in high-strength, high-P soils. Nevertheless, this work demonstrates that root hairs are a valuable trait for plant growth and nutrient acquisition under combined soil stresses. Selecting plants with superior root hair traits is important for improving P uptake efficiency and hence the sustainability of agricultural systems

Impact of Tillage Methods on Environment, Energy and Economy

ISSN 2210-4410, eISBN 9783319990767Soil tillage involves the mechanical manipulation of soils used for crop production. Tillage is done to prepare an optimal seedbed, to loosen compacted soil layers, to control weeds, to increase aeration, to incorporate plant residues into the soil, to facilitate water infiltration and soil moisture storage, and to control soil temperature. Nonetheless, soil tillage is one of the highest energy-consuming, environment-polluting and expensive technological processes in agriculture. Conventional tillage with ploughing is the most widely used practice. Conventional tillage has low efficiency, requires high-powered tractors with high fuel consumption and greenhouse gases emissions. Moreover, the cost of conventional tillage is high, and the influence on the soil structure, degradation, leaching of nutrients and the most fertile soil is negative. Here we review the impact of tillage methods on soil quality, environment and economy. Due to the disadvantages of conventional tillage, sustainable tillage area increases each year by 4-6 million ha worldwide. Under sustainable tillage such as minimal or no-tillage, the total soil surface modified by the wheels of agricultural machinery is 20-40% lower than for conventional tillage. Sustainable tillage preserves better soil physical properties and biological processes. A comparison of tillage methods show that no-tillage has the highest energy efficiency ratio of 14.0, versus 12.4 for deep ploughing. The most expensive tillage operation is deep ploughing. The use of agricultural machinery under sustainable tillage conditions and preparation of soils without using a plough can reduce costs from 25% to 41%, compared with conventional tillageVytauto Didžiojo universitetasŽemės ūkio akademij