Growth and yield traits and yield
The plant height and no. of branches plant
-1 were significantly affected by conventional and mechanization practices at 1% level of significance (Table 1). Significantly taller plants (1.95 m) with more no. of branches plant
-1 (20.6) were registered with CPs than MPs (1.73 m, 18.6).
The MPs and CPs showed significant effect on seed index and yield of pigeonpea at 1% level of significance (Table 1). Pigeonpea under MPs has produced significantly higher seed yield (1362 kg ha
-1), stalk yield (1664 kg ha
-1) and biological yield (3023 kg ha
-1) than that of CPs (1169, 1465 and 2634 kg ha
-1), respectively. This could be ascribed to relatively more no. of pods and significantly higher seed index under MPs over CPs. Further, placement of seed at optimal depth in moist zone in the soil when sown with seed cum ferti drill might have facilitated better germination, establishment and production of better yield traits in mechanization. In the current study, mechanical intercultivation has helped in loosening the soil, uprooting and exposing the weeds finally leading to their death. Additionally, it has provided better soil physical conditions for better aeration, increased infiltration (Fig 1) and moisture storage due to breakage of soil crust. Further, intra row weeding with hand held weed scraper is faster, beneficial, less tedious and economical than traditional methods. Furthermore, use of paddy combiner facilitated in faster and simultaneous mechanical harvesting/threshing. The results of this study were found to be in line with that of
Patil and Basavaraja (2018) who reported 52.5% higher yield in pigeonpea in mechanized farms than non-mechanized farms.
Korwar et al. (2012) reported 24% saving in seed and 30% less fertilizer with the use of mechanized sowing operation using precision planter in pigeonpea.
Man-days and time requirement
MPs consumed only 52.5 man-days and 102.5 hours ha
-1 against 95 man-days and 170 hours ha
-1 in conventional practices indicating a saving of 42.5 man-days and 67.5 hours ha
-1 with mechanization (Table 2). More man-days were required for harvesting and threshing followed by weed management and plant protection measures. Use of seed cum ferti drill helped in reducing the man days by 75% besides placing the seeds at optimum soil depth than the traditional approach.
Singh et al. (2012) suggested use of either bed planter or 6-row inclined plate planter for planting pigeonpea for promising results.
Korwar et al. (2012) recommended precision planter cum herbicide applicator for various rainfed crops for precise and simultaneous sowing cum fertilizer and herbicide application. Further, this approach also helps in completion of sowing over a larger area during a short sowing window, before the soil moisture is exhausted in rainfed crop ecosystem
(Kumar et al., 2020).
In manual method, application of fertilizers followed by seed sowing were done ‘behind the plough’ duly involving cattle pair and 10 labour which took 15 hours ha
-1 to complete the operation. But, in mechanized sowing with seed cum ferti drill, seeding and fertilizer application were done in a single operation with minimal man-days (2.5 ha
-1) and time (5.0 hours ha
-1) thus reducing the man days and workforce by 75% and 66.7%, respectively over CPs.
In addition to exhausting the soil moisture, nutrients and aeration, weeds hinder the harvesting process and lower the quality of the seed
(Kumar et al., 2023). Hence, timely weed control especially during critical period of crop weed competition (45-60 DAS) is utmost important. Machine aided interculture and intra row weeding helped to save 10 man-days (44.4%) and 12.5 hours time ha
-1 (27.8%) in the present study (Table 2). Further, the plant protection with motorized power sprayer reduced the time requirement by 37.5% over that of knapsack sprayers. Tractor operated boom sprayers will be of great use in large pigeonpea fields for expedite coverage. Now a days, the use of drones is becoming popular for plant protection in view of their quick, precise and uniform coverage, in relatively larger areas. It takes only 0.83 hours ha
-1 with drone against 7.5 hours ha
-1 with battery sprayer and 4.25 hours ha
-1 with motorized power sprayer, besides saving 90% water requirement
(Ramanjaneyulu et al., 2021).
The pigeonpea is a tall growing thick woody stem plant with multiple branches. Traditional way of harvesting with sickle by human labour is laborious, risky, tedious and sometimes injurious to the labour. Harvesting early at high moisture content increases the drying cost and delaying the harvesting leads to yield loss due to shattering, birds/rodents damage, pests and diseases. Further, threshing is again a laborious process requiring beating the sticks against hard surface followed by drying in the sun. Prolonged storage of harvested material may be affected by high humidity, frost or untimely rains leading to impairment of seed quality
(Benaseer et al., 2018). In the current investigation, use of paddy combiner which does both the harvesting and threshing in single operation could reduce the man-days by 25.0 (90.9%) and time by 26.25 hours ha
-1 (87.5%).
Kumar et al. (2019) suggested 26.61 m s
-1 and 2.0 kmph as optimum values for peripheral velocity and forward speed for running the paddy combiner to reduce damage to the seed, less processing and shattering losses besides higher threshing efficiency in pigeonpea. Further,
Lohan et al., (2007) suggested for use of lower cylinder speed and high concave clearance in rasp bar and spike tooth threshing cylinders due to less seed damage.
Wallis et al. (1981) in Australia and Fiji and
Gupta (1990) in India have successfully demonstrated paddy combiner and wheat combiner for mechanized harvesting and threshing of short and extra early short duration varieties of pigeonpea, respectively.
Regarding residue management, the stalks were heaped and burnt as a part of CPs. On the contrary, in MPs, rotary mulcher was run over the remaining stalks in the field which resulted in tiny pieces followed by incorporation during subsequent tillage operations. This technique has the potential to improve the soil fertility, porosity and regulating other physical soil properties like hydraulic conductivity and bulk density (
Senthil Kumar and Thilagam, 2015). Additionally, residue recycling of N fixing leguminous crop like pigeonpea not only supports soil conservation but also sustains long term crop productivity and subsequently lowers the reliance on synthetic inputs (
Devaraj and Isaac, 2023).
Economics
The economic returns were found to be significant at 1% and cost of cultivation at 5% level of significance (Table 1). Adoption of MPs (Rs. 47,202 ha
-1) have not only reduced the cost of cultivation by 12.5%, but also accrued higher gross returns (Rs. 80,524 ha
-1) by 16.6% and net returns (Rs. 33,325 ha
-1) by 120.7% besides higher B:C ratio (1.73) over CPs (Rs. 53,947, 69,047, 15,100 ha
-1, 1.32). It was mainly owing to reduced cost of about Rs. 6,750 ha
-1 (Table 1) due to saving of 45 man-days ha
-1 under MPs (Table 2). Further, the conventional methods require more no. of workers for performing same operations, higher wage rate and less operational efficiency than mechanical methods. Earlier,
Patil and Basavaraja (2018) reported significant reduction in man-days but higher net returns in mechanized farms than non-mechanized in pigeon pea.
Energy indices
All the energy indices were influenced at 1% level but net energy at 5% level of significance (Table 3). MPs have significantly dominated the CPs for energy input, energy output, net energy and energy output efficiency. Conversely, significantly higher energy productivity, energy ratio and energy profitability with CPs over MPs. This was because MPs required 50.7% higher energy but produced only 16.3% higher energy output following less significant improvement in yield
i.e. 16.5% higher seed yield only over CPs. It means less seed yield per unit energy consumed in MPs.
