ABSTRACT
Aerobic rice production system provides a sustainable alternative to the traditional rice cultivation. To evaluate the agronomic and economic effect of intercropping aerobic rice with four leafy vegetables, field experiments were conducted at University of Agriculture Science Bangalore research station, India during 2017 and 2018. The experiments consisted of 9 treatments with 4 replications and, a Randomized Completely Block Design was applied. The treatments were as follows: Intercropping (IC1): rice+amaranth; IC2: rice + coriander; IC3: rice + spinach, and IC4: rice + fenugreek plus other 5 treatments of solecrops (SC), SC5: rice, SC6: amaranth, SC7: coriander, SC8: spinach, and SC9: fenugreek. Results showed that intercropping produced significantly better plant growth and higher yields than sole crops. The rice-spinach intercrop produced highest rice grain yield (7,651 kg ha-1), vegetable yield (25,508 kg ha-1), land equivalent ratio (2.13), rice equivalent yield (16,153 kg ha-1), production efficiency (107.69 kg day-1), area time equivalent ratio (1.23) and system harvest index (0.77). Net return and benefit cost ratio of rice-spinach intercropping were also higher than that of sole crops. This suggests that intercropping of aerobic rice with leafy vegetables can be productive and economically efficient.
Key words: Aerobic rice, intercropping, leafy vegetables, productivity.
Rice is the second most widely cultivated cereal after corn and is staple food for more than half of world’s population (CGIAR, 2016). Asia-Pacific region produces and consumes over 90% of world rice (Nirmala, 2017). In many parts of the world, rice is predominantly transplanted and flood-irrigated with standing water throughout the season. In Asia especially China and India, 75% of harvested rice is irrigated and lowland type. The flooded rice production system is usually preferred as a weed management strategy (Shaibu et al., 2015). Due to present day water resource crisis and high demand for irrigation of other crops, aerobic rice production has been introduced and adopted in several countries including India (Kadiyala et al., 2012; Priyanka et al., 2012).
Aerobic rice is a lowland rice planting system that involves growing drought tolerant high yielding rice varieties in non-flooded soils and with no puddling (Bouman and Toung, 2001; Patel et al., 2010). The aerobic rice has low water requirement as compared to lowland rice and can save about 45% water (Lampayan et al., 2010). Besides being water saver, aerobic rice production is often affected by several abiotic and biotic stress factors such as nutrient deficiencies (Jiban et al., 2019), nematodes (Kreye et al., 2009) and high weed pressure (Anwar et al., 2010; Kumalasari and Bergmeier, 2014). Consequently, these conditions lower yield potential of aerobic rice leading to heavy losses.
Intercropping is a practice that involves growing of two or more crop species at the same time in a field, and is traditionally used as an important strategy in sustainable agriculture (Bybee-Finley and Ryan, 2018). Intercropping is known to increase crop yields, reduce pests and disease and suppress weeds. To explore the potential of intercropping, aerobic rice has also been intercropped with other crops. For instance in Nigeria, farmers intercropped upland rice with cassava and vegetables (Okonji et al., 2012). Jadeyegowda et al. (2019) evaluated different aerobic rice intercropping systems and their effect on rice growth and yield. Intercropping of aerobic rice with watermelon alleviate Fusarium wilt by restraining spore formation and improving soil heath (Ren et al., 2008). Increased crop biomass helped in suppressing weed in aerobic rice when intercropped with vegetables (Habimana et al., 2019). The objectives of this study were to assess the effect of intercropping aerobic rice with leafy vegetables on growth, yield and to assess its economic efficiency.
This study was conducted during two consecutive summer seasons in 2017 and 2018 at research experimental station of University of Agricultural Sciences, Bangalore (UASB), India. The experiment was laid out following RCBD design with nine treatments and four replications. The treatments were: Intercropping (IC1): rice+amaranth, IC2: rice + coriander, IC3: rice+spinach, and IC4: rice + fenugreek. The remaining 5 treatments were sole crops (SC), namely: SC5: rice, SC6: amaranth, SC7: coriander, SC8: spinach, and SC9: fenugreek. Farmyard manure was applied to all plots at a rate of 10 tonnes ha-1 15 days before sowing. The rice and vegetable seeds were directly sown into the soil and common fertilizers such as urea, single superphosphate and muriate of potash were applied. The experimental site had red sandy loam soil with pH 6.7, organic carbon 0.58%, available N 362 kg ha-1, available P 43 kg ha-1 and available K 289 kg ha-1. Anaerobic rice genotype MAS946-1 was used in this study. All treatments were managed until maturity and data were collected using five plant samples.
To compare performance of sole rice treatments with the other leafy vegetable intercrops, data on growth, yield and yield attributes were recorded and pooled for 2017 and 2018 and averages were examined through Least Significant Difference (LSD) test at 5% degree of significance. Leafy vegetable, rice grain and straw yield were expressed in ha-1 before the analysis of variance (ANOVA). The productivity of intercropping was examined by calculating several parameters. The Land Equivalent Ratio is used to decide which crop is suitable. It denotes relative land area under sole crop required to produce the same yield as obtained under a mixed or an intercropping system at the same level of management. It is the ratio of land required by pure crop to produce the same yield as intercrop. Land Equivalent Ratio (LER) was calculated following Willey (1979). Rice equivalent yield (REY) refers to the yields of different intercrops/crops which are converted into equivalent yield of any one crop based on price of the produce. This was calculated by considering the grain yield of component crops and the existing market price of aerobic rice crop and leafy vegetables components as following Verma and Modgal (1983). Based on REY and duration of the cropping system, production efficiency (PE) was also calculated and expressed as kg day-1 according to Habimana et al., (2019). It was based on the rice equivalent yield and duration of cropping system. Area time equivalent ratio (ATER) provides more realistic comparison of the yield of intercropping over monocropping in terms of time taken by component crops in the intercrop. It was used to compare yield advantages of intercropping components over a stand-alone cropping system, and was calculated following Hiebsch and Macollam (1980). The data on the system harvest index (SHI) in the intercropping experiment of rice-leafy vegetables was calculated as following:
To evaluate economic performance of different intercropping systems, gross and net returns were estimated as of Sujan et al., (2017a, b) in their studies. Benefit cost ratio (BCR) of components crop yield was calculated following the calculation of Bala et al. (2020), Sujan et al. (2021), and Sahota and Malhi (2012).
Growth, yield and yield attributes of rice under intercropping system
Results for rice growth parameters, rice yield attributes, grain yield and straw yield have shown significant difference among the treatments (Table 1). Plant growth, rice grain yield (7,651 kg ha-1) and straw yield (9,687 kg ha-1) were highest in the IC3 (rice + spinach), whereas rice sole crop showed lowest plant growth, yield, yield attributes and straw yield as compared to the intercrops (Table 1). The higher amount of rice grain yield in IC3 could be as a result of better yield attributing characters such as number of productive rice tillers per hill (34.10), total number of grain per panicle (160.54) and thousand grain weight (23.72 g). Good performance of the IC3 could be attributed to better growth performance (Table 1). Besides, the large canopy of spinach produced minimum weed population in those plots, which increased the equilibrium thus benefiting the crop in maximum utilization of the accessible resources such as increased soil moisture availability during intercrop period. These results are in conformity with the findings of Mian et al., (2010).
Yield of leafy vegetables
Under intercropping, the yield of amaranth, coriander, spinach and fenugreek were 14029, 11642, 25508 and 13095 kg ha-1, respectively (Table 1). However, when planted as a sole crop, leafy vegetables produced higher yield than when intercropped. The reduction in yield could be as a result of competition for resources during intercropping hence indicating that rice crop was dominant over the leafy vegetables (Oroka and Omororegie, 2007).
Rice equivalent yield (REY) and other efficiencies
All intercropping efficiencies, land equivalent ratio (LER), rice equivalent yield (REY), production efficiency (PE), area time equivalent ratio (ATER) and system harvest index (SHI) were significantly different among the treatments (Table 2). The LERs for all types of intercrops were higher than sole crop, thus indicating that intercropping rice crop with leaf vegetables was more beneficial than sole rice production. This is indicated by better growth and grain yield advantage (80-113%), which is exhibited under intercropping as indicated in Table 1. Higher LER could be due to better use of natural resources as previously indicated by Jabbar et al. (2009) and Udhaya and Kuzhanthaivel (2015). The REYs were higher in all the intercrops with rice-spinach intercrop producing the highest REY (16,153 kg ha-1) (Table 2). High REY indicate the increased productivity in intercrops as compared to sole crop. These results confer with previous studies of Nagwa et al. (2014) and Rayhan et al. (2014). The maximum PE (107.69 kg day-1) was found in rice-spinach intercrop. The findings showed that the intercrops components stayed in the field for a short time and leaf yields were also high resulting to high biomass production per day. Ibni et al. (2005) and Nazrul and Shaheb (2014) reported similar findings. The ATER values showed an average up to 23% in intercropping combination comparison with the sole rice cropping pattern. Intercropping rice with spinach also produced highest ATER of 1.23. Similar trends were reported in research studies of Mian et al., (2011) and Nagwa et al., (2014). The SHI, all intercrops showed higher values and HI of 0.42 for the sole rice crop. These results confer with the findings of Hugar and Palled (2008), Jabbar et al., (2009) and Mohan (2012).
Economic efficiency
Highest gross return (2,56,842 Indian Rupees (INR) ha-1), net returns (INR 212,860 ha-1), and benefit cost ratio (BCR = 5.84) were obtained when rice was intercropped with spinach (Table 3). Both sole rice crop and spinach produced lower gross return, net return and BCR as compared to rice-spinach combination. BCR increased in IC3 mainly due to the increase in rice grain and straw yield under intercropping system. High aerobic rice yield and leaf yield of vegetables, which in turn increased gross and net returns. Generally, intercropping was economically efficient as compared to sole crops. Similar results were also reported in pea-maize intercropping systems (Yang et al., 2018).
The results of this study showed that all four intercropping combination treatments were appropriate in relation to the stand-alone aerobic rice crop and leafy vegetable treatments. However, aerobic rice intercropping with spinach leafy vegetable has exhibited high production and economic efficiency with respect to biological yield, intercropping efficiencies and benefit cost ratio. Hence, intercropping could be recommended to aerobic rice growers in the studied area.
The authors have not declared any conflict of interests.
The authors thank Netaji Subhas International Fellowship (NSIF) and Indian Council of Agricultural Research (ICAR) for funding this research study.
REFERENCES
|
Anwar PM, Juraimi AS, Man A, Puteh A, Selamat A, Begum M (2010). Weed suppressive ability of rice (Oryza sativa L.) germplasm under aerobic soil conditions. Australian Journal of Crop Science 4(9):706-717.
|
|
|
|
Bala H, Ghosh AK, Kazal MMH, Rahman MS, Sultana M, Sujan MHK (2020). Floating gardening in Bangladesh: a sustainable income generating activity in wetland areas. International Journal of Agricultural Research, Innovation and Technology 10(1):87-93.
Crossref
|
|
|
|
|
Bouman BAM, Tuong TP (2001). Field water management to save water and increase its productivity in irrigated low land rice. Agricultural Water Management 49:11-30.
Crossref
|
|
|
|
|
Bybee-Finley KA, Ryan MR (2018). Advancing intercropping research and practices in industrialized agricultural landscapes. Agriculture 8(6):80.
Crossref
|
|
|
|
|
CGIAR (2016). The global staple.
|
|
|
|
|
Habimana S, Kalyana Murthy KN, Nanja Reddy YA, Mudalagiriyappa M, Vasantha Kumari R, Hanumanthappa DC (2019). Impact of aerobic rice-leafy vegetables intercropping systems on weed management. Advances in Horticultural Science 33(3):365373. https://doi.org /10.13128/ahs-24266
|
|
|
|
|
Hiebsch CK, Macollam RE (1980). Area-×-time equivalency Ratio: A method for evaluating the productivity of intercrops. Agronomy Journal 75:15-22.
Crossref
|
|
|
|
|
Hugar HY, Palled YB (2008). Studies on maize-vegetable intercropping system. Karnataka Journal of Agricultural Sciences 21(2):162-161.
|
|
|
|
|
Ibni ZMS, Ahmad R, Haq AU (2005). Performance of rice in different rice-based cropping systems sown after different legume and non-legume crops. Journal of Animal and Plant Sciences 15(3-4):79-81.
|
|
|
|
|
Jabbar A, Ahmad R, Bhatti IH, Virk ZA, Din W, Khan MM (2009). Assessment of yield advantages, competitiveness and economic benefits of diversified direct-seeded upland rice-based intercropping systems under strip geometry of planting. Pakistan Journal of Agricultural Sciences 46(2):96-101.
|
|
|
|
|
Jadeyegowda M, Bandi AG, Reddy VC, Kalyana Murthy KN (2019). Identification of suitable intercrops performance under aerobic rice (Oryza sativa L.) cultivation. Journal of Pharmacognosy and Phytochemistry 8(2):1419-1422.
Crossref
|
|
|
|
|
Jiban KB, Shahjahan K, Sazzadur R, Kamrun N, Mirza H (2019). Managing Abiotic Stresses With Rice Agriculture to Achieve Sustainable Food Security. Advances in Rice Research for Abiotic Stress Tolerance. Woodhead Publishing pp. 23-45, ISBN 9780128143322.
Crossref
|
|
|
|
|
Kadiyala MDM, Mylavarapu RS, Li YC, Reddy GB, Reddy MD (2012). Impact of aerobic rice cultivation on growth, yield, and water productivity of rice-maize rotation in semiarid tropics. Agronomy Journal 104:1757-1765.
Crossref
|
|
|
|
|
Kumalasari NR, Bergmeier E (2014). Nutrient assessment of paddy weeds as ruminant feed in Java. Livestock Research for Rural Development 26(4):59.
|
|
|
|
|
Kreye C, Bouman BAM, Reversat G, Fernandez L, Vera Cruz C, Elazegui F, Faronilo JE, Llorca L (2009). Biotic and abiotic causes of yield failure in tropical aerobic rice. Field Crops Research112: 97-106.
Crossref
|
|
|
|
|
Lampayan RM, Bouman BAM, de Dios JL, Espiritu AJ, Soriano JB, Lactaoen AT, Faronilo JE, Thant KM (2010). Yield of aerobic rice in rainfed lowlands of the Philippines as affected by nitrogen management and row spacing. Field Crops Research 116:165-174.
Crossref
|
|
|
|
|
Mian MAK, Hamidullah ATM, Alam MS, Matin MQI, Banu MB (2010). Productivity and nutrient balance in maize-based intercropping under different nutrient levels. Bangladesh Journal of Agricultural Research 6(2):61-71.
|
|
|
|
|
Mian MAK, Alam MS, Hossain J (2011). Weed growth, yield and economics of maize + spinach intercropping. Bangladesh Journal of Weed Science 2(1-2):41-46.
|
|
|
|
|
Mohan KR (2012). Standardization of maize (Zea mays L.) + field bean (Dolichos lablab L.) intercropping system in southern transitional zone of Karnataka. M.Sc. (Agri.) Thesis, University of Agriculture Sciences of Bangalore, Karnataka, India.
|
|
|
|
|
Nagwa RA, Faissal FA, Al-Hussein SAH (2014). Physiological studies on intercropping of some legumes on sewy date palms. World Rural Observations 6(4):81-88.
|
|
|
|
|
Nazrul MI, Shaheb MR (2014). Screening of pulse crops for fallow land utilization in Sylhet region. Bangladesh, Agronomy Journal 15(2):59-65.
|
|
|
|
|
Nirmala B (2017). Rice Production in Asia: Key to Global Food Security. Proceedings of the National Academy of Sciences, India Section B: Biological Sciences.
|
|
|
|
|
Okonji CJ, Ajayi EA, Okeleye KA, Oyekanmi AA (2012). Upland rice based intercropping system among farmers in selected villages in Ogun State in South west of Nigeria. Agriculture and Biology Journal of North America 3(5):225-232.
Crossref
|
|
|
|
|
Oroka FO, Omoregie AU (2007). Competition in rice-cowpea intercrops as affected by nitrogen fertilization and plant population. Scientia Agricola (Piracicaba, Braz) 64(6):621-629.
Crossref
|
|
|
|
|
Patel DP, Das A, Munda GC, Ghosh PK, Borodoloi JS, Kumar M (2010). Evaluation of yield and physiological attributes of high-yielding rice cultivars under aerobic and flood-irrigated management practices in mid-hills ecosystem. Agricultural Water Management 97(9):1269-1276.
Crossref
|
|
|
|
|
Priyanka S, Jitesh B, Babu S (2012). Aerobic rice, a new approach of rice cultivation. International Journal of Research in BioSciences 1(1):1-6.
|
|
|
|
|
Rayhan SMD, Mahmudul IN, Sarker MJU (2014). Production potentials and economics of chickpea rice based cropping system in Sylhet area. Bangladesh Journal of Agricultural Research 39(3): 479-490.
Crossref
|
|
|
|
|
Ren LX, Su SM, Yang XM, Xu YC, Huang QW, Shen QR (2008). Intercropping with aerobic rice suppressed Fusarium wilt in watermelon. Soil Biology and Biochemistry 40(3):834-844.
Crossref
|
|
|
|
|
Sahota TS, Malhi SS (2012). Intercropping barley with pea for agronomic and economic considerations in northern Ontario. Agricultural Science 3(7):889-895.
Crossref
|
|
|
|
|
Shaibu YA, Banda Mloza HR, Makwiza CN, Chidanti Malunga J (2015). Grain yield performance of upland and lowland rice varieties under water saving irrigation through alternate wetting and drying in sandy clay loams of southern Malawi. Experimental Agriculture 51(2):313-326.
Crossref
|
|
|
|
|
Sujan HK, Islam F, Kazal MH, Mondal RK (2017a). Profitability and resource use efficiency of potato cultivation in Munshiganj district of Bangladesh. SAARC Journal of Agriculture 15(2):193-206.
Crossref
|
|
|
|
|
Sujan MHK, Islam F, Azad MJ, Rayhan SJ (2017b). Financial profitability and resource use efficiency of boro rice cultivation in some selected area of Bangladesh. African Journal of Agricultural Research 12 (29):2404-2411.
Crossref
|
|
|
|
|
Sujan MHK, Kazal MMH, Ali MS, Rahman MS (2021). Cost-benefit analysis of mud crab fattening in coastal areas of Bangladesh. Aquaculture Reports 19:100612.
Crossref
|
|
|
|
|
Udhaya ND, Kuzhanthaivel RL (2015). Analysis of light transmission ratio and yield advantages of pigeon pea in relation to intercrop and different plant population. African Journal of Agricultural Research 10(8):731-736.
Crossref
|
|
|
|
|
Verma SP, Modgal SC (1983). Production potential and economics of fertilizer application as resource constraints in maize -wheat crop sequence. Himachal Journal of Agricultural Research 9(2):89-92.
|
|
|
|
|
Willey RW (1979). Intercropping- its importance and research needs, Part-I, competition and yield advantages. Field Crop Abstracts 32:1-10.
|
|
|
|
|
Yang C, Fan Z, Chai Q (2018). Agronomic and economic benefits of pea/maize intercropping systems in relation to N fertilizer and maize density. Agronomy 8(4):52.
Crossref
|
|
