RESEARCH AND INNOVATION FOR ENHANCING WATER USE EFFICIENCY

ENHANCING LAND USE AND WATER PRODUCTIVITY THROUGH ALTERNATE RAISED AND SUNKEN BEDS IN LOWLANDS OF BIHAR

DR. VINOD KUMAR&

DR. M P. SINGH

Rajendra Agricultural University, Pusa Samastipur (Bihar)

INTODUCTION Low land rice area is mostly located in the eastern region and is about 14.4 million

ha, which accounts 32.4 per cent of the total area under rice crop in India. The average productivity of rice in low land areas ranges from 1.0 to 1.2 tonnes per

ha as against the national average productivity of 1.9 tonnes per ha. Shallow lowlands of Bihar comprising 1.6 lakh ha out of total 4.0 lakh ha

waterlogged area, where the root zone soil remains saturated or waterlogged

throughout the kharif as well as part of the rabi season. In most of the cases the farmers are growing rice both in kharif and rabi seasons

which alone is often not as remunerative to the areas where vegetables or other rabi

crops are being taken. In such lowlands, especially with shallow water inundation of less than 50 cm,

modification in field topography through construction of alternate raised and

sunken beds helps to improve the physical environment of the root zone and

creates proper condition for the growth of aerobic crops(Singh et al., 2005). Crop diversification is the need of the hour for better returns from the unit area to

the farmers.

OBJECTIVES

To study the effect of cropping system and irrigation under raised and sunken beds with different crops on:

1 Rice equivalent yield2 Net return3 Water productivity4 Land Use & suitability

MATERIALS & METHODSA field experiment was conducted at Experimental

farm, Rajendra Agricultural University, Pusa, Samastipur, Bihar (India), during 2009-11.

The soil of the experimental plot was calcareous, silty clay loam in texture, low in available nitrogen and phosphorus and medium in potassium content.

Depth of water applied each time - 6 cm. Total rainfall during crop season – 76.57cm.

The experiment was laid out in split plot design with 4 cropping systems in main plot and 3 irrigation regimes for vegetables in sub plot.

TREATMENTSCropping System: (Main Plots - 6.3 m x 5.0 m)

 

C1- Original lowland rice (Rice – Rice in Kharif & Rabi) C2- Alternate raised and sunken bed system (Rice-Rice in sunken bed and Brinjal – Cabbage + Radish in raised bed) C3- Alternate raised and sunken bed system (Rice-Rice in sunken bed and Okra – Cauliflower + Radish in raised bed) C4 -Alternate raised and sunken bed system (Rice-Rice in sunken bed and Cowpea–Tomato + Radish in raised bed) Irrigation Regimes: (for vegetables only) (Sub-Plot - 1.8 m x 5.0 m)

I1- 30 mm CPE (Cumulative Pan Evaporation) I2- 40 mm CPE I3- 50 mm CPE

The rice equivalent yield was maximum (97.40 q/ha) under Rice-Rice in sunken bed and Brinjal–Cabbage + Radish in raised bed cropping system, which was significantly superior over Cowpea–Tomato + Radish in raised bed (90.23 q/ha), Okra–Cauliflower + Radish in raised bed (86.48 q/ha) and lowland rice (80.31q/ha).

Treatments Cropping systemIrrigation C1 C2 C3 C4 Mean

I1- 30 mm CPE 81.56 99.25 89.22 95.26 90.57I2- 40 mm CPE 80.61 97.69 86.99 91.04 89.08

I3- 50 mm CPE 78.76 95.27 83.23 87.38 86.16

Mean 80.31 97.40 86.48 90.23

Source S. Em + CD at 5 %Cropping sequence (C) 1.02 3.04

Irrigation (I) 0.60 1.69C X I 1.19 NS

Table -1.Effect of cropping system and irrigation on pooled rice equivalent yield (q/ha).

Rice equivalent yield was highest (90.57 q/ha) at 30 mm CPE. However, there was non-significant difference between irrigation regimes of 30 mm CPE and 40 mm CPE, but there was significant difference between irrigation regimes of 40 mm CPE (89.08 q/ha) and 50 mm CPE (86.16 q/ha).

Net return was significantly higher in Brinjal–Cabbage + Radish in raised bed cropping system (52954 Rs./ha)as compared to Cowpea–Tomato + Radish in raised bed (46445 Rs./ha), Okra–Cauliflower + Radish in raised bed (42589 Rs./ha) and lowland rice (36845 Rs./ha).

Treatments Cropping systemIrrigation C1 C2 C3 C4 Mean

I1- 30 mm CPE 37573 54114 44601 48376 46166I2- 40 mm CPE 37058 53226 43084 46913 45070

I3- 50 mm CPE 35904 51522 40083 44046 42889Mean 36845 52954 42589 46445

Source S. Em + CD at 5 %Cropping system (C) 1072 3128

Irrigation (I) 544 1540C X I 1089 NS

Table – 2 Effect of cropping system and irrigation on pooled net return (Rs./ha).

         Net return were highest (46166 Rs./ha) at 30 mm CPE. However, there was non-significant difference between irrigation regimes of 30 mm CPE and 40 mm CPE, but there was significant difference between irrigation regimes of 40 mm CPE (45070 Rs./ha) and 50 mm CPE (42889 Rs./ha).

Irrigation regimes Cropping system

C1 C2 C3 C4 Mean

I1- 30 mm CPE 228.63 423.89 348.92 378.80 345.06

I2- 40 mm CPE 234.01 437.51 353.59 385.36 352.62

I3- 50 mm CPE 235.49 445.54 345.97 380.29 351.82

Mean 232.71 435.65 349.49 381.48

Table -3. Effect of cropping system and irrigation regime on pooled water productivity (Rs./ha-cm).

Maximum water productivity (435.65 Rs./ha-cm) was recorded in Brinjal–Cabbage+Radish in raised bed followed by Cowpea–Tomato+Radish in raised bed (381.48 Rs./ha-cm), Okra–Cauliflower + Radish in raised bed (349.49 Rs./ha-cm) and lowland rice (232.71 Rs./ha-cm). The lowest water productivity of 345.06 Rs./ha-cm was recorded with irrigation regime 30 mm CPE and increased with 40 mm CPE (352.62 Rs./ha-cm) and was closely followed by 50 mm CPE (351.82 Rs./ha-cm).

Irrigation regimes Cropping system

C1 C2 C3 C4

Land use index (%) 76.71 83.56 83.56 86.30

Yield equivalent ratio - 1.21 1.08 1.12

Table - 4. Effect of cropping system on pooled Land Use Index (%) and Yield Equivalent Ratio.

Land utilization index was the highest (86.30 %) in case of Cowpea–Tomato+Radish in raised bed followed by Okra-Cauliflower+ Radish in raised bed (83.56 %) and Brinjal-Cabbage+ Radish in raised bed (83.56 %) and the lowest (76.71 %) in case of low land rice cropping system. Duration of separate vegetable crops in raised bed was lesser but fetching higher net return and there is scope of introduction of short duration catch crops like leafy vegetables and green gram during summer season. Yield equivalent ratio was the maximum (1.21) in Brinjal-Cabbage+ Radish in raised bed followed by Cowpea-Tomato+ Radish (1.12) and Okra-Cauliflower + Radish (1.08) showing enhanced land use.

Boro rice in Sunken bed Kharif vegetables on raised bed

Rabi vegetables on raised bed

C0NCLUSION

Higher rice equivalent yield, net return, water productivity and

land utilization could be obtained with rice in sunken bed and

suitable vegetable crops in raised bed by modifying the

lowlands in alternate raised and sunken beds. Irrigation at 40

mm CPE to rabi vegetables is most suitable.

Singh, R., Kundu, D.K., Mohanty, R.K., Ghosh, S., Kumar, A. and Kanan. K. 2005. Alternate raised and sunken bed system for crop diversification in lowlands. Extension Bulletin. Water Technology centre for Eastern Region (ICAR), Bhubaneswar, India.

REFERENCE