Increased absorption and use of nutrients induced by Si is an indicator for tolerance to water deficit in a common bean cultivar cultivated in the field with and without application of K

Abstract

Introduction: Reduced water content in the soil triggers physiological, biochemical, and morphological damage to plants, aggravated by nutritional deficiency. One possible strategy to mitigate this damage comprises the use of silicon (Si). This study investigated whether Si can mitigate the damage caused by water deficit through nutritional mechanisms in bean plants grown under field conditions. Furthermore, it investigated whether the effectiveness of Si is influenced by water availability in the soil and the Si dose supplied.

Methods: Therefore, two split-plot experiments were carried out: with and without K supply. In both experiments,the treatments comprised a 3 × 4 factorial scheme. Treatments included three water regimes: 80% (no water deficit), 60% (moderate water deficit), and 40% (severe water deficit) of the soil's water retention capacity. Moreover, they comprised four doses of Si supplied via fertigation-0 kg/ha, 4 kg/ha, 8 kg/ha, and 12 kg/ha-arranged in a randomized block design with four replications.

Results and discussion: The appropriate dose of Si to be applied increased with the severity of the water deficit, with the recommended dose being 6 kg/ha, 7 kg/ha, and 8 kg/ha of Si for adequate water conditions, moderate water deficit, and severe water deficit, respectively.

Keywords: beneficial element; nutritional efficiency; plant nutrition; water deficiency; water effciency.

Figure 1

Meteorological data of the experimental area during bean cultivation. Maximum temperature (T° Max.), minimum temperature (T° Min.), and global radiation (A); maximum relative humidity (RH Max.), minimum relative humidity (RH Min.), and precipitation (B).

Figure 2

Accumulation of silicon (Si) (A, B) and carbon (C) (C, D) in the shoot of common bean plants cultivated without water deficit (WWD) [80% of the water retention capacity (WRC)], with deficit moderate water deficit (MWD) (60% of WRC), and with severe water deficit (SWD) (40% of WRC), combined with doses of Si supplied via fertigation: 0 kg/ha, 4 kg/ha, 8 kg/ha, and 12 kg/ha, without (K0) and with (K1) potassium fertilization. Letters show differences for water regimes (WR) at each dose of Si (p < 0.05, Tukey’s test). * and ** indicate significance at 1% and 5% probability, respectively, and ns indicates non-significance by the F test.

Figure 3

Accumulation of nitrogen (N) (A, B), phosphor (P) (C, D), potassium (K) (E, F), calcium (Ca) (G, H), magnesium (Mg) (I, J), and sulfur (S) (K, L) in the shoot of common bean plants cultivated without water deficit (WWD) [80% of the water retention capacity (WRC)], with deficit moderate water deficit (MWD) (60% of WRC), and with severe water deficit (SWD) (40% of WRC), combined with doses of Si supplied via fertigation: 0 kg/ha, 4 kg/ha, 8 kg/ha, and 12 kg/ha, without (K0) and with (K1) potassium fertilization. Letters show differences for water regimes (WR) at each dose of Si (p < 0.05, Tukey’s test). * and ** indicate significance at 1% and 5% probability, respectively, and ns indicates non-significance by the F test.

Figure 4

Accumulation of manganese (Mn) (N) (A, B), zinc (Zn) (C, D), copper (Cu) (E, F), and iron (Fe) (G, H) in the shoot of common bean plants cultivated without water deficit (WWD) [80% of the water retention capacity (WRC)], with deficit moderate water deficit (MWD) (60% of WRC), and with severe water deficit (SWD) (40% of WRC), combined with doses of Si supplied via fertigation: 0 kg/ha, 4 kg/ha, 8 kg/ha, and 12 kg/ha, without (K0) and with (K1) potassium fertilization. Letters show differences for water regimes (WR) at each dose of Si (p < 0.05, Tukey’s test). * and ** indicate significance at 1% and 5% probability, respectively, and ns indicates non-significance by the F test.

Figure 5

Efficiency of use the nitrogen (NUE) (A, B), phosphorus (PUE) (C, D), potassium (KUE) (E, F), calcium (CaUE) (G, H), magnesium (MgUE) (I, J), and sulfur (SUE) (K, L) in the common bean plants cultivated without water deficit (WWD) [80% of the water retention capacity (WRC)], with deficit moderate water deficit (MWD) (60% of WRC), and with severe water deficit (SWD) (40% of WRC), combined with doses of Si supplied via fertigation: 0 kg/ha, 4 kg/ha, 8 kg/ha, and 12 kg/ha, without (K0) and with (K1) potassium fertilization. Letters show differences for water regimes (WR) at each dose of Si (p < 0.05, Tukey’s test). * and ** indicate significance at 1% and 5% probability, respectively, and ns indicates non-significance by the F test.

Figure 6

Efficiency of use of carbon (CUE) (A, B) and dry matter of shoot (C, D) in the common bean plants cultivated without water deficit (WWD) [80% of the water retention capacity (WRC)], with deficit moderate water deficit (MWD) (60% of WRC) and with severe water deficit (SWD) (40% of WRC), combined with doses of Si supplied via fertigation: 0 kg/ha, 4 kg/ha, 8 kg/ha, and 12 kg/ha, without (K0) and with (K1) potassium fertilization. Letters show differences for water regimes (WR) at each dose of Si (p < 0.05, Tukey’s test). * and ** indicate significance at 1% and 5% probability, respectively, and ns indicates non-significance by the F test.

Figure 7

Principal component analysis of accumulation variables (Ac) of C, N, P, K, Ca, Mg, S, Mn, Cu, Fe and Zn; use efficiencies (UE) of C, N, P, K, Ca, Mg, and S; and dry matter production (DM) of common bean plants cultivated without water deficit (WWD) [80% of the water retention capacity (WRC)], with moderate water deficit (MWD) (60% of WRC), and with severe water deficit (SWD) (40% of WRC), combined with doses of Si supplied via fertigation: 0 kg/ha, 4 kg/ha, 8 kg/ha, and 12 kg/ha, without (K0) and with (K1) potassium fertilization. G1, G2, G3, and G4 refer to grouping treatments into hierarchical groups using Euclidean distance.

Figure 8

Pearson’s correlation network between the variable accumulation (Ac) of C, N, P, K, Ca, Mg, S, Mn, Cu, Fe, and Zn; use efficiencies (EU) of C, N, P, K, Ca, Mg, and S; and dry matter production (DM) in common bean plants cultivated without water deficit (WWD) [80% of the water retention capacity (WRC)], with moderate water deficit (MWD) (60% of WRC), and with severe water deficit (SWD) (40% of WRC), combined with doses of Si supplied via fertigation: 0 kg/ha, 4 kg/ha, 8 kg/ha, and 12 kg/ha, without (K0) and with (K1) potassium fertilization. Positive correlations are highlighted in green, and the stroke thickness indicates the strength of the correlation.