Crop Productivity Enhancement under Soybean Based Cropping System through Harvested Rain Water in Malwa Region

Rainwater harvesting, the small-scale collection and storage of runoff for irrigated agriculture, is recognized as a sustainable strategy for ensuring food security, especially in monsoonal landscapes in the developing world (Kimberly et al., 2016). Within a context of scarce water resources for agriculture, rainwater harvesting constitutes a promising alternative (Juan et al., 2019). Rainwater harvesting technologies are a critical factor for productivity of agricultural crops (Schlenker and Lobe, 2010). The hydrological and geological status of any watershed having Vertisol are the major factors for deciding the type and size of water harvesting tank. Rainwater harvesting is commonly practiced in areas, where the rainfall is insufficient for crop growing. Due to the intermittent nature of run-off events, it is necessary to store the maximum possible amount of rainwater during the rainy season so that it may be used at a later date (Qadir et al., 2007 and Oweis et al., 2003). If the soil is underlained by fragmented basaltic murram with high percolation rate, the lining of such excavated farm pond is very essential. Presently, HDPE (High Density Polyethylene) films of 500 µm or cross layer-reinforced silpaulin with 300-350g/m² are commonly used (Rao et al., 2017). On the other hand, if soil is very deep, excavated farm pond may store runoff water for longer time to be utilized during prolonged dry spell or providing lifesaving /supplemental/pre sowing irrigation to kharif and rabi crop. Rainwater harvesting implies harvesting, storing and conserving rainwater directly, in a farmed area that is generally smaller than the size of the catchment area (Kiggundu et al., 2018 and Boers et al., 1982). The location wise heterogeneity, therefore reflect on effectiveness of lined and unlined water harvesting tank. However, not much information is available on comparative performance of these two types of tanks on farm productivity. Further, due to limited storage capacity, long-term use of rainwater is only possible in conjunction with groundwater (Hubert and Agnes, 2017). In order to meet the increased irrigation water, augmentation of existing water sources by development of additional sources of water and conjunctive use of surface and ground water will be needed (Mall et al., 2006). The objective of the study was to assess the impact of increased water availability on farm productivity and farm income through water harvesting tank only on station and through conjunctive use of ground water and surface water in small sized water harvesting tank in a farmer’s field condition.

The study was initiated at research station of All India Coordinated Research Project for Dryland Agriculture at College of Agriculture, Indore (M.P.) by considering an old tank which was constructed during 1991(22^o42'02.0" N and 75^o54'20.5" E). Since this tank, area was underlain by fragmented basaltic murram with very high percolation/seepage rate i.e. 18 cm/day. It was not possible to retain the sufficient water for its utilization during kharif and rabi. During 2018-19, this tank was reshaped and provided with a suitable lining material HDPE sheet which retained 1781 m³ water (Top length 42 m, width 21 m, bottom length 37.2 m, bottom width 16.2 m with 1:1 side slope and depth 2.4 m). During 2018-19 kharif season in a block of 50 m × 50 m, two crops soybean sown and maize were planted. These two crops were harvested and in the same area four crops, namely chickpea, sweetcorn, potato and onion were planted at different time by utilizing harvested water from the lined tank. These crops were provided irrigation through various irrigation system viz. rain gun, drip and flood from time to time till their harvesting.  Similarly, in a village Ningnoti district Indore a farm pond of size 630 m3 was constructed during 2018-19 in a farmer’s field (22^o47'87.8"N and 75^o59'75.7"E). The soil of the field is very deep vertisol having almost no seepage and percolation. The farmer owns only 0.87ha cultivated field thus only area 15m × 11m was utilized for the tank construction. In the monsoon season of 2018-19, these two tanks got filled up with runoff water to their full capacity. Since the rainfall during 2018-19 monsoon was well distributed, no water from those two tanks were utilized for providing irrigation to kharif crops. However, these two tanks were provided with horizontal submersible pump (Pandubbi) for irrigating the crops (wheat, chickpea, potato, onion, garlic, sweet corn etc.) grown during rabi season. With this in a view, a study was carried out to compare the productivity and economics of the soybean based cropping system with the provision of water harvesting tank. This study was considering these two water harvesting tanks (one lined on station and one unlined on farm) located at different location during 2018-19. It was carried out by considering all the harvested water for its better utilization under two different conditions viz. with exclusive use of harvested water and conjunctive use of surface water + ground water. 

All India Coordinated Research Project for Dryland Agriculture research station
 
The date wise irrigation amount and time taken is reported in the Table 1. The data showed that water applied in chickpea, sweat corn, onion and potato was 11.8 cm (100 m³), 75.73 cm (615 m³), 74.11 cm (189 m³) and 46.34 cm (457 m³) respectively. Maximum number of irrigation were provided in sweat corn (8) while least in chickpea (1). Water budget of tank presented in Table 2, which indicate that out of total capacity (1781m³) 418 m³ water remained unused as dead storage. Detailed of crop yields with their B: C ratio also analyzed and presented in Table 3. Data resulted that among five cropping sequences system Maize-Sweet corn gave the maximum net return of Rs.150851 per hectare with B:C 4.35. Soybean and Chickpea crop yield were 1630kg/ha and 1173 kg/ha respectively. Net return and B:C of Soybean and Chickpea were reported 37037Rs/ha, 2.85 and 33939 Rs/ha, 3.61 respectively.
 

 

 
Farmer field village Ningnoti
 
Since this tank was constructed on the farmer’s field, the farmer not only utilized the harvested water at once but also used this tank as storage tank. Farmer filled it with tube well water instead of directly providing irrigation to field crops through tubewell water. This tube well provided water at reduce rate and takes longer time to irrigate the field, which was not sufficient to cultivate any crop. A high discharge pump was used to lift the stored water from the pond for irrigating the nearby crop. During kharif season not irrigating crops due to favorable monsoon except onion before harvesting. However during rabi season conjunctive use of surface water and ground water was made by him. Thus, the details of the irrigation is presented in Table 4. The data showed that water applied in onion (kharif), garlic, coriander, wheat and onion (Rabi) was 5.16 cm (129 m³), 24.25 cm (291 m³), 10.8 cm (270 m³), 31.08 cm (777 m³) and 11.64 cm (291 m³) respectively. Maximum number of irrigation were provided in garlic (8) while least in onion (kharif). Water budget of tank in farmer field presented in Table 5, which indicate that out of total capacity (630 m³) 34.61 m³ water remained unused as dead storage. Detailed of crop yields with their B: C ratio also analyzed and presented in Table 6. Data resulted that among four cropping sequences system Soybean-Garlic gave the maximum net return of Rs.173000 per hectare with B:C 3.16. Soybean and wheat crop yield were 1400 kg/ha and 6000 kg/ha respectively. Net return and B:C of soybean and chickpea were reported 29000 Rs/ha, 2.45 and 90000 Rs/ha, 4.0 respectively.
 

 

 

 
Comparative performance
 
It is clearly indicated thatthat for on station for irrigating 50 m × 50 m area with different crops during rabi season required 1363.2 m³ water. On the other hand the farmer irrigated his 0.75 ha area by utilizing 596 m³ harvested + 1164.2 m³ refilled water. Hence total of 1760.4 m³ utilized (Table 7). It is also observed that with efficient use of surface and ground water with a small size water harvesting tank is sufficient enough to provide additional and supplemental irrigation for growing crops. Under purely rainfed condition, a large sized water harvesting tank is required for successfully growing the rabi crops. Instead of irrigating the crops directly with tube well water, it is beneficial to storage it in the farm pond and then utilizing it with higher discharge pump. This ensures better irrigation water management and time and labour saving in irrigation with the storage of tube well water in the farm pond. Micro irrigation system can also be adopted with availability of irrigation water at uniform discharge rate.