caa a22 4500 606219463 CHVBK 20210128101118.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s11104-014-2294-3 doi (NATIONALLICENCE)springer-10.1007/s11104-014-2294-3 Biochar but not humic acid product amendment affected maize yields via improving plant-soil moisture relations [Elektronische Daten] [Ghulam Haider, Hans-Werner Koyro, Farooqe Azam, Diedrich Steffens, Christoph Müller, Claudia Kammann] Aims: Biochar (BC) and humic acid product (HAP) soil amendments may improve plant performance under water-limited conditions. Our aim was to investigate if BC and HAP amendments, alone or in combination, will have positive and synergistic effects. Methods: A three-factorial fully randomized study was carried out in the greenhouse for 66days, including the factors ‘BC', ‘HAP' and ‘water regime'. Maize (Zea mays var. ‘Amadeo' DKC-3399) was grown in pots (6kg sandy soil pot−1) amended with/without BC (0, 1.5 and 3%; w/w) and with/without HAP (0 or an equivalent of 8kg ha−1). Two water regimes, limited and frequent (H2O limit , H2O frequ ), were applied after day 28 following seedling establishment at 60% water holding capacity (WHC). In the H2O limit treatment, the soil water content was allowed to drop until wilting symptoms became visible (25-30% WHC) while in H2O frequ the WHC was brought to 60% of the maximum on a daily basis Results: BC but not HAP, added alone or in combination with BC, significantly increased the biomass yield and the water and N use efficiency of plants at both water regimes. The BC-mediated relative increase in the yield was equal with both watering regimes, refuting initial hypotheses. BC had generally a stimulating effect on water relations and photosynthesis, it increased the relative water content and the leaf osmotic potential, decreased the stomatal resistance and stimulated the leaf gas exchange (transpiration). Both, BC and pure HAP addition, stimulated photosynthesis by increasing the electron transport rate (ETR) of photosystem II (PSII) and of the ratio between effective photochemical quantum yield to non-photochemical quenching (Y(II)/Y(NPQ), revealing reduced heat dissipation. Conclusions: Biochar use in poor sandy soils can improve plant growth by improving soil-plant water relations and photosynthesis under both H2O frequ and H2O limit conditions. HAP loading, however, did not improve the effect of biochar or vice versa. Springer International Publishing Switzerland, 2014 Biochar nationallicence Eco-physiology nationallicence Photosynthesis nationallicence Humic acid products nationallicence Maize nationallicence Sandy soil nationallicence Water holding capacity nationallicence Water stress nationallicence Osmotic potential nationallicence Haider Ghulam Department of Plant Ecology, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut Koyro Hans-Werner Department of Plant Ecology, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut Azam Farooqe AMKA Biosolutions, 14 Ellman Street, 0157, Sunderland Ridge, Pretoria 0001, South Africa aut Steffens Diedrich Department of Plant Nutrition, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut Müller Christoph Department of Plant Ecology, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut Kammann Claudia Department of Plant Ecology, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut Plant and Soil Springer International Publishing 395/1-2(2015-10-01), 141-157 0032-079X 395:1-2<141 2015 395 11104 https://doi.org/10.1007/s11104-014-2294-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-014-2294-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Haider Ghulam Department of Plant Ecology, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut NATIONALLICENCE 700 1- Koyro Hans-Werner Department of Plant Ecology, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut NATIONALLICENCE 700 1- Azam Farooqe AMKA Biosolutions, 14 Ellman Street, 0157, Sunderland Ridge, Pretoria 0001, South Africa aut NATIONALLICENCE 700 1- Steffens Diedrich Department of Plant Nutrition, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut NATIONALLICENCE 700 1- Müller Christoph Department of Plant Ecology, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut NATIONALLICENCE 700 1- Kammann Claudia Department of Plant Ecology, Justus-Liebig University Giessen, Heinrich-Buff Ring 26-32, 35392, Giessen, Germany aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 395/1-2(2015-10-01), 141-157 0032-079X 395:1-2<141 2015 395 11104