Changes in grain weight of two wheat cultivars, CH58 (A) and XN9871 (B) under organic fertilizer and different water regimes.

<p>CK: control; M: organic fertilizer; WS: water stress; WW: well-watered. Bars are LSD at <i>P</i>≤0.05.</p

Effects of organic fertilizer on flag leaf (A) POD activity, (B) SOD activity and (C) MDA content of two wheat cultivars under water stress and well-watered conditions at 14 d after anthesis.

<p>CK: control; M: organic fertilizer; WS: water stress; WW: well-watered. All data were presented as the mean± SD of six replicates. Duncan’s multiple range test in the SPSS System was used to separate the means, different lowercase letters represent significant different (<i>P</i>≤0.05).</p

Physiological mechanisms contributing to increased water-use efficiency in winter wheat under organic fertilization

<div><p>Improving the efficiency of resource utilization has received increasing research attention in recent years. In this study, we explored the potential physiological mechanisms underlying improved grain yield and water-use efficiency of winter wheat (<i>Triticum aestivum</i> L.) following organic fertilizer application. Two wheat cultivars, ChangHan58 (CH58) and XiNong9871 (XN9871), were grown under the same nitrogen (N) fertilizer rate (urea-N, CK; and manure plus urea-N, M) and under two watering regimes (WW, well-watered; and WS, water stress) imposed after anthesis. The M fertilizer treatment had a higher P_n and lower g_s and T_r than CK under both water conditions, in particular, it significantly increased WRC and Ψ_w, and decreased EWLR and MDA under WS. Also, the M treatment increased post-anthesis N uptake by 81.4 and 16.4% under WS and WW, thus increasing post-anthesis photosynthetic capacity and delaying leaf senescence. Consequently, the M treatment increased post-anthesis DM accumulation under WS and WW by 51.5 and 29.6%, WUE_B by 44.5 and 50.9%, grain number per plant by 11.5 and 12.2% and 1000-grain weight by 7.3 and 3.6%, respectively, compared with CK. The grain yield under M treatment increased by 23 and 15%, and water use efficiency (WUE_g) by 25 and 23%, respectively. The increased WUE under organic fertilizer treatment was due to elevated photosynthesis and decreased T_r and g_s. Our results suggest that the organic fertilizer treatment enabled plants to use water more efficiently under drought stress.</p></div

Changes in chlorophyll content in the flag leaf of two wheat cultivars, CH58 (A) and XN9871 (B) under organic fertilizer and different water regimes.

<p>CK: control; M: organic fertilizer; WS: water stress; WW: well-watered. Bars are LSD at <i>P</i>≤0.05. Effects of organic fertilizer on photosynthetic characteristics.</p

Effects of organic fertilizer, water conditions and cultivars on leaf relative water content (LRWC), leaf water potential (Ψ_w), excised-leaf water loss rate (EWLR), and water retention capacity (WRC) of two winter wheat cultivars.

<p>Effects of organic fertilizer, water conditions and cultivars on leaf relative water content (LRWC), leaf water potential (Ψ_w), excised-leaf water loss rate (EWLR), and water retention capacity (WRC) of two winter wheat cultivars.</p

Effects of organic fertilizer, water conditions and cultivars on DM accumulation and N uptake after anthesis and pre-anthesis DM and N remobilization and remobilization efficiency.

<p>Effects of organic fertilizer, water conditions and cultivars on DM accumulation and N uptake after anthesis and pre-anthesis DM and N remobilization and remobilization efficiency.</p

Changes in Fv/Fm of the flag leaf of two wheat cultivars, CH58 (A) and XN9871 (B) under organic fertilizer and different water regimes.

<p>CK: control; M: organic fertilizer; WS: water stress; WW: well-watered. Bars are LSD at <i>P</i>≤0.05.</p

Changes in (A, E) net photosynthetic rate (P_n), (B, F) transpiration rate (T_r), (C, G) stomatal conductance (g_s), and (D, H) water-use efficiency at the leaf level (WUE_i) during the grain-filling stage of two cultivars, CH58 (A-D) and XN9871 (E-H) under organic fertilizer and two water regimes.

<p>Organic fertilizer: M; control: CK; WS: water stress; WW: well-watered. Bars are LSD at <i>P</i>≤0.05.</p

Effects of organic fertilizer, water conditions and cultivars on root weight (RWt), leaf weight (LWt), stem weight (StemWt), ear weight (EWt), total dry biomass (TWt), 1000-grain weight (TGW), grain number per plant (GN), root/shoot ratio (R/S), grain yield per plant and harvest index (HI).

<p>Effects of organic fertilizer, water conditions and cultivars on root weight (RWt), leaf weight (LWt), stem weight (StemWt), ear weight (EWt), total dry biomass (TWt), 1000-grain weight (TGW), grain number per plant (GN), root/shoot ratio (R/S), grain yield per plant and harvest index (HI).</p

Changes in carbohydrates, nitrogen compounds and the C:N ratio in sorghum leaf 8 during drought progression.

<p>A, Soluble sugars. B, Starch. C, Total non-structural sugars. D, Total nitrogen content. E, Soluble proteins. F, Free amino acids. G, C:N ratio. Data represent mean ± SE (n = 3). Asterisks indicate statistically significant differences between treatments (* <i>P</i>≤0.05; ** <i>P</i>≤0.01; *** <i>P</i>≤0.001).</p