**2.14 Effect of rice husk biochar on number of seed/cob, 100 grain weight (g), and grain yield (g) of maize under drought stress conditions**

Drought stress affected anthesis, grain filling of maize associated with reduction of number seed/cob, 100 grain weight, and ultimately grain yield. Decrease of photosynthesis under drought conditions also affected grain yield. Application of biochar increased photosynthesis efficiency, anthesis, and grain filling, thereby increasing yield of maize. The number of seed per cob, 100 grain weight, and grain yield varied significantly with biochar doses under drought conditions (**Table 10**).

Under control condition (80%of FC), 60% of field capacity, and 40% of field capacity, highest numbers of seed per cob were 353.0, 335.0, and 334.6, respectively, when biochar was applied at 20 t/ha, and lowest seeds per cob were 163.0, 147.3, and 139.0, respectively, when no biochar was applied. Under control condition highest 100 grain weight (27.7 g) was found when biochar was applied at 20 t/ha, and it was lowest (21.8 g) when no biochar was applied. Under 60% of field capacity, highest 100 grain weight (26.5 g) was found when biochar was applied at 20 t/ha, and it was lowest (20.7 g) when no biochar was applied. Under 40% of field capacity, highest 100 grain weight (25.0 g) was found when biochar was applied at 20 t/ha, and it was lowest (20.0 g) when no biochar was applied. Under control condition (80% of FC), 60% of field capacity, and 40% of field capacity, highest

*Amelioration of Drought Tolerance in Maize Using Rice Husk Biochar DOI: http://dx.doi.org/10.5772/intechopen.88824*


#### **Table 10.**

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.

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

CV (%) 0.0 15.7 2.15

**Number of cob Length of cob (cm) Diameter of cob (cm)**

c

**40% of FC**

**Control 60% of FC**

15.3a–c 3.9a 3.6a–c 3.5a–c

**40% of FC**

**Control 60% of FC**

0 1.0a 1.0a 1.0a 15.9a–c 13.2bc 12.1c 3.5a–c 3.2c 3.1c 5 1.0a 1.0a 1.0a 16.5ab 14.7a–c 14.6a–c 3.6a–c 3.3bc 3.2c 10 1.0a 1.0a 1.0a 17.2ab 15.1a–c 15.0a–c 3.8ab 3.5a–c 3.3a–c

**Biochar doses (t/ha)**

*Maize - Production and Use*

**Table 9.**

*conditions.*

**70**

**Control 60% of FC**

*Figure having similar letter did not vary significantly.*

20 1.0a 1.0a 1.0a 17.6a 15.3aa–

**40% of FC**

**2.14 Effect of rice husk biochar on number of seed/cob, 100 grain weight (g),**

Drought stress affected anthesis, grain filling of maize associated with reduction

**and grain yield (g) of maize under drought stress conditions**

of number seed/cob, 100 grain weight, and ultimately grain yield. Decrease of photosynthesis under drought conditions also affected grain yield. Application of biochar increased photosynthesis efficiency, anthesis, and grain filling, thereby increasing yield of maize. The number of seed per cob, 100 grain weight, and grain yield varied significantly with biochar doses under drought conditions (**Table 10**). Under control condition (80%of FC), 60% of field capacity, and 40% of field capacity, highest numbers of seed per cob were 353.0, 335.0, and 334.6, respectively, when biochar was applied at 20 t/ha, and lowest seeds per cob were 163.0, 147.3, and 139.0, respectively, when no biochar was applied. Under control condition highest 100 grain weight (27.7 g) was found when biochar was applied at 20 t/ha, and it was lowest (21.8 g) when no biochar was applied. Under 60% of field capacity, highest 100 grain weight (26.5 g) was found when biochar was applied at 20 t/ha, and it was lowest (20.7 g) when no biochar was applied. Under 40% of field capacity, highest 100 grain weight (25.0 g) was found when biochar was applied at 20 t/ha, and it was lowest (20.0 g) when no biochar was applied. Under control condition (80% of FC), 60% of field capacity, and 40% of field capacity, highest

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

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

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

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


#### **Table 11.**

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

highest P were 9.18, 8.00, and 7.96 ppm, respectively, when biochar was applied at 20 t/ha, and lowest P were 7.49, 7.48, and 7.44 ppm, respectively, when no biochar was applied. The initial K was 0.16 meq/100 g soil, and after crop harvest under control condition (80% of FC), 60% of field capacity, and 40% of field capacity, highest K were 0.18 meq/100 g soil, 0.18 meq/100 g soil, and 0.17 meq/100 g soil, respectively, when biochar was applied at 20 t/ha, and lowest K were 0.17 meq/ 100 g soil, 0.17 meq/100 g soil, and 0.17 meq/100 g soil, respectively, when no biochar was applied. [53] reported biochar increased plant available nutrient in soil. [54] reported drought reduced N, P, and K levels in soil. [55] observed that the addition of biochar to soils increased soil phosphorus (P), soil potassium (K), and total soil nitrogen (N).

**3. Conclusions**

maize yield at drought conditions.

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

Bangladesh, for funding the work.

There is no conflict of interest.

**Acknowledgements**

**Conflict of interest**

**Author details**

**73**

Md. Abdul Mannan\* and Mariam Akter Shashi

provided the original work is properly cited.

\*Address all correspondence to: mannanbsmrau@yahoo.com

University, Gazipur, Bangladesh

Department of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agricultural

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Application of rice husk biochar increased plant height, days to maturity, total dry weight, chlorophyll content, plant water relations, SPAD value, exudation rate and reduced proline content, and days to flowering of maize under drought conditions. In maize plant drought stress tolerance ameliorate rice husk biochar and increased cob diameter, cob length, 100 grain weight of cob, seed /cob and finally

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

We are grateful to the University Grants Commission (UGC), Government of
