**2.13 Effect of rice husk biochar on number of cob, length of cob, and diameter of cob of maize under drought stress**

The number of cob was one per plant, and there is no significant difference among numbers of cob per plant under drought stress condition with different biochar doses (**Table 9**).

Drought affected growth of maize. Length of cob of maize was reduced under drought conditions. When biochar was applied at different doses, the cob length was increased under drought conditions (**Table 9**). Under control condition highest cob length (17.6 cm) was found when biochar was applied at 20 t/ha, and it was lowest (15.9 cm) when no biochar was applied. Under 60% of field capacity, highest


### **Table 8.**

*Effect of rice husk biochar on shoot, root, and total dry weight of maize under drought conditions.*

The highest dry weight of stem were 27.28 g, 26.25 g and 22.75 g in control, 60% of field capacity and 40% of field capacity, respectively, when biochar was applied

*Effect of rice husk biochar on dry weight of cob sheath, leaf and stem of maize under drought conditions.*

**Cob sheath (g/plant) Leaf (g/plant) Stem (g/plant)**

**40% of FC**

**Control 60% of FC**

**40% of FC**

**Control 60% of FC**

 12.8bc 11.7bc 10.3c 37.2d–g 35.2fg 34.4g 24.8ab 21.4ab 19.0b 13.1bc 12.6bc 11.4bc 39.8a–d 36.4e–g 36.2e–g 25.4ab 22.3ab 20.6ab 14.5bc 14.2bc 12.9bc 40.3a–c 39.4a–d 37.7c–f 26.8a 25.2ab 21.3ab 19.7a 15.5ab 14.8abc 42.0a 41.5ab 38.6b–e 27.2a 26.2a 22.7ab

*Effect of rice husk biochar on proline content of maize under drought conditions. Bar indicates LSD at 5% level*

at 20 t/ha, and lowest dry weights of cob sheath were 12.8, 11.7, and 10.3 g, respectively, when no biochar was applied. Under control condition (80% of FC), 60% of field capacity, and 40% of field capacity, highest dry weights of leaf were 42.0, 41.5, and 38.6 g, respectively, when biochar was applied at 20 t/ha, and lowest

CV (%) 21.9 4.6 17.3

**Table 7**. Effect of rice husk biochar on dry weight of cob sheath, leaf, and stem of maize under drought conditions, 37.2, 35.2, and 34.4 g, respectively, when no biochar was applied. Under control condition (80%of FC), 60% of field capacity, and 40% of field capacity, highest dry weights of stem were 27.2, 26.2, and 22.7 g, respectively, when biochar was applied at 20 t/ha, and lowest dry weights of stem were 24.8, 21.8, and 19.0 g, respectively, when no biochar was applied. [43] found drought stress reduced dry weight of plant parts by affecting photosynthesis. [44] reported that application of biochar increased dry weight of field-grown

dry weights of leaf were.

**Biochar doses (t/ha)**

*Maize - Production and Use*

**Figure 4.**

*of significance.*

**Control 60% of FC**

*Figure having similar letter did not vary significantly.*

**40% of FC**

wheat.

**68**

**Table 7.**


#### **Table 9.**

*Effect of rice husk biochar on number of cob, length of cob, and diameter of cob of maize under drought conditions.*

grain yields were 96.7, 89.7, and 84.5 g/plant, respectively, when biochar was applied at 20 t/ha, and lowest grain yields were 40.7, 35.9, and 27.8 g/plant, respectively, when no biochar was applied. Similar result was reported by [50]. [51] observed water stress reduced yield of triticale. [52] reported biochar increased pod

*Effect of rice husk biochar on the number of seed/cob, 100 grain wt. (g), and grain yield (g) of maize under*

CV (%) 35.5 16.70 37.40

**Number of seed /cob 100 grain weight (g) Grain yield (g/plant)**

**40% of FC** **Control 60% of FC**

**40% of FC**

**Control 60% of FC**

 163.0bcd 147.3cd 139.0d 21.8a–c 20.7bc 20.0c 40.7cd 35.9cd 27.8d 273.0a–d 244.0a–d 164.3b–d 23.4a–c 21.7a–c 21.4a–c 58.6a–d 57.5a–d 34.9cd 10 300.0ab 297.0a–c 288.3a–d 26.8ab 23.0a–c 21.5a–c 79.5ab 68.9a–c 61.0a–d 353.0a 335.0a 334.6a 27.7a 26.5a–c 25.0a–c 96.7a 89.7ab 84.5ab

**2.15 Effect of rice husk biochar on N, P, and K in soil under drought stress**

highest total N (0.14%) was found when biochar was applied at 20 t/ha; it was lowest (0.10%) when no biochar was applied. Under 60% of field capacity, highest total N (0.13%) was found when biochar was applied at 20 t/ha, and it was lowest (0.10%) when no biochar was applied. Under 40% of field capacity, highest total N (0.11%) was found when biochar was applied at 20 t/ha, and it was lowest (0.09%) when no biochar was applied. The initial P was 7.24 ppm, and after harvest under control condition (80% of FC), 60% of field capacity, and 40% of field capacity,

and P and K under stress and nonstressed conditions (**Table 11**).

Under drought conditions biological activities as well as nutrients in soil are greatly affected. As a result macronutrients such as N, P, and K are reduced. Application of rice husk biochar showed positive effects on total nitrogen content

The initial total N was 0.17%, and after crop harvest under control condition, the

**Total N (%) P (ppm) K (meq/100 g soil) 0.172 7.24 0.169**

> **40% of FC**

**Control 60% of FC**

**40% of FC**

**After harvest**

 0.10a 0.10a 0.09a 7.49bc 7.48bc 7.44c 0.17a 0.17a 0.17a 0.11a 0.11a 0.10a 7.96bc 7.74bc 7.61bc 0.17a 0.17a 0.17a 0.12a 0.11a 0.11a 9.13a 7.98bc 7.64bc 0.18a 0.17a 0.17a 0.14a 0.13a 0.11a 9.18a 8.00b 7.96bc 0.18a 0.18a 0.17a

CV (%) 7.0 4.0 1.5

*Effect of rice husk biochar on N, P, and K in soil under drought conditions.*

**Control 60% of FC**

**40% of FC**

yield of soybean under saline conditions.

**Control 60% of**

*DOI: http://dx.doi.org/10.5772/intechopen.88824*

*Figure having similar letter did not vary significantly.*

**FC**

**40% of FC**

*Amelioration of Drought Tolerance in Maize Using Rice Husk Biochar*

**Biochar doses (t/ha)**

**Table 10.**

*drought conditions.*

**Before sowing**

**Table 11.**

**71**

**Biochar doses (t/ha)**

**Control 60% of FC**

*Figure having similar letter did not vary significantly.*

cob length (15.3 cm) was found when biochar was applied at 20 t/ha, and it was lowest (13.2 cm) when no biochar was applied. Under 40% of field capacity, highest total cob length (15.3 cm) was found when biochar was applied at 20 t/ha, and it was lowest (12.1 cm) when no biochar was applied. Cob diameter of maize was reduced under drought stress conditions, and reduction was higher at 40% of field capacity than at 60% of field capacity. Biochar application increased cob diameter under drought conditions (**Table 9**). Under control condition highest cob diameter (17.6 cm) was found when biochar was applied at 20 t/ha, and it was lowest (15.9 cm) when no biochar was applied. Under 60% of field capacity, highest cob diameter (15.3 cm) was found when biochar was applied at 20 t/ha, and it was lowest (13.2 cm) when no biochar was applied. Under 40% of field capacity, highest total cob diameter (15.3 cm) was found when biochar was applied at 20 t/ha, and it was lowest (12.1 cm) when no biochar was applied. [47] reported biochar increased yield of lettuce. Reductions in plant yield have been reported in snap bean by [48]. [49] observed biochar application increased maize yield in semiarid conditions.
