Agricultural and environmental applications of biochar (BC) to soils have received increasing attention as a possible means of improving productivity and sustainability. Most previous studies have focused on tropical soils and more recently temperate soils. However, benefits of BC addition to desert soils where many productivity constraints exist, especially water limitations, have not been widely explored. Thus, three experiments were designed using a desert soil from Saudi Arabia to address three objectives: (1) to evaluate the effect of BCs produced from date palm residues added at 8 t ha −1 on wheat growth, (2) to determine the effect of BC addition and BC aging in soil on water retention, and (3) to reveal the effect of BC on selected soil physical (bulk density, BD; total porosity; TP) and chemical (pH; electrical conductivity, EC; organic matter, OM; cation exchange capacity, CEC) properties. The feedstock (FS) of date palm residues were pyrolyzed at 300, 400, 500, and 600 • C, referred to here as BC300, BC400, BC500, and BC600, respectively. The BC products produced at low temperatures were the most effective in promoting wheat growth when applied with the NPK fertilizer and in enhancing soil water retention, particularly with aging in soil, whereas high -temperature BCs better improved the selected soil physical properties. The low-temperature BCs increased the yield approximately by 19% and improved water retention by 46% when averaged across the incubation period. Higher water retention observed with low-temperature BCs can be related to an increased amount of oxygen-containing functional groups in the low-temperature BCs, rendering BC surfaces less hydrophobic. Only the BC300 treatment showed a consistent positive impact on pH, OM, and CEC. Pyrolysis temperature of date palm residue along with aging are key factors in determining the potential benefit of BC derived from date palm residues added to sandy desert soil.crop yield is largely dependent on BC production temperature and the feedstock (FS) [5][6][7]. In a recent review, it was reported that the fertilizing value of BC and its nutrient availability, especially N and P, decrease with increasing pyrolysis temperature [5]. Therefore, the effect of BC on crop yield and plant nutrition was found to be variable, and its use as a sole amendment was not always effective, having its supplementation with mineral fertilizers sometimes necessary to promote crop growth [8][9][10][11][12][13][14][15][16]. Some studies found BC to be the most effective when it is applied with mineral fertilizers [8,14,[17][18][19]. Therefore, positive impact of BC on soil fertility and crop yield is not always certain, and it highly depends on FS, BC production temperature, and most importantly soil type [3,[5][6][7]20].BC benefits to soil also include improvement of soil physical properties. For instance, soil bulk density (BD) and porosity was found to be improved after BC application [20][21][22][23][24][25][26]. BC was also reported to increase the soil ability to retain ...

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Information on how soil texture and related soil properties affect corn (Zea mays L.) nitrogen (N) response is needed to improve N management in corn production. We conducted a study at 12-site yr in Quebec to assess the effect of N rate (0–250 kg N ha−1) and soil surface textural groups [clay, loam, sandy belonging to the gleysolic soil order (Sg), and sandy belonging to the podzolic soil order (Sp)] on corn grain yield, stover yield, total N uptake (TNU), nitrogen uptake efficiency (NUE), thousand kernel weight (TKW), test weight, and chlorophyll meter readings (CMR). Corn was more responsive to N rate in the clay soil textural group for most of the parameters due to lower soil N supply, and least responsive in the Sp group, except for test weight and CMR, due to possibly greater leaching in this group. The CMR at flowering accounted for 87%, 87%, 82%, and 25% of the variation in grain yield, TNU, TKW, and test weight, respectively. This study suggests that soil surface texture has a major influence on corn N response, but other soil properties such as drainage may also be important.