Optimizing Productivity and Economics of Maize + Legumes Intercropping: A Study on the Impact of Natural and Organic Farming Practices

Maize (Zea mays L.) is a major source of world¢s food energy and contains a significant amount of proteins, vitamins and minerals. Compared to other cereal crops, it has a higher production potential. Maize is a heavy feeder of plant nutrients and growing of these crops alone over the years will barren the land and cause for decline in productivity. Inclusion of legumes in rotation or raising them in association with these crops have been advocated by various workers to sustain the soil health and due importance was given for achieving higher productivity (Gebru, 2015). The yield advantage of cereals in intercropping system with leguminous crops probably occurred from the difference in timing of utilization of resources by different crops. The productivity of maize based intercropping systems in India has been maintained with the use of high analysis chemical fertilizers. Chemical fertilizers have the capacity to meet the nutrient requirements of these crops in an intensive cropping system but regular use of these fertilizers lead to nutrient imbalance, which has a detrimental effect on both the soil health and crop productivity. Therefore, to ensure food, nutritional, soil and environmental security, conventional production systems need to shift towards eco-friendly agriculture systems that combine low ecological footprint to produce more crops.
               
Organic farming is one such step towards environment friendly techniques that is taken to ensure sustainable agricultural production. Although, in organic farming, there is a significant need for organic manures such as farm yard manure, green manure, compost, vermi-compost and non-edible cake etc. to meet the nutritional needs of organic crops (Kumar, 2015). Moreover, small and marginal farmers owe a small number of animals so in order to meet the nutritional requirement of the crops; they need to purchase the bulky organic manures from outside sources which further add the transportation costs in the cost of cultivation. In that case, this practice does not remain economically feasible for small and marginal farmers. Padma Shree Subhash Palekar presented a novel idea called "Zero Budget Natural Farming (ZBNF)," which is low-input, climate-resilient farming thus promotes farmers to use inexpensive, locally obtained inputs rather than synthetic fertilizers and pesticides from industrial sources (Palekar, 2006). The core idea of natural farming is to encourage the growth of beneficial microbes without relying on external fertilizers or synthetic pesticides. Legumes, in this context, are valuable because they capture atmospheric nitrogen, enriching the soil (Raveena et al., 2024). He has recommended four aspects of ZBNF that are critical viz., beejamrit, jeevamrit, acchadana and whapasa. He has recommended the application of jeevamrit at 21 days interval. Hence, keeping in view the above-mentioned points and jeevamrit application duration, the present investigation entitled “The influence of natural and organic farming techniques on the productivity and economics of maize based intercropping systems’’ was carried out with the aim of increasing the production of the crops per unit area in the present study and different intervals (14, 21 and 28 days) of jeevamrit application were tested in different maize based intercropping systems.

Field experiment was conducted at CSK HPKV, Palampur (32°09'N, 76°5'E), during kharif 2020 and 2021. The soil of the experimental site was silty clay loam in texture, acidic in reaction (pH 5.4), high in organic carbon and medium in available nitrogen, phosphorus and potassium. The experiment was laid out in randomized block design comprising of thirteen treatments viz.,T₁-Maize + lobia– Wheat + gram and jeevamrit spray at 14 days interval, T₂- Maize + lobia- Wheat + gram and jeevamrit spray at 21 days interval, T₃- Maize + lobia - Wheat + gram and jeevamrit spray at 28 days interval, T₄- Maize + soybean - Wheat + lentil and jeevamrit spray at 14 days interval, T₅- Maize + soybean - Wheat + lentil and jeevamrit spray at 21 days interval, T₆- Maize + soybean - Wheat + lentil and jeevamrit spray at 28 days interval, T₇- Maize sole -Wheat sole and jeevamrit spray at 14 days interval, T₈-Maize sole -Wheat sole and Jeevamrit spray at 21 days interval, T₉-Maize sole-Wheat sole and jeevamrit spray at 28 days interval, T₁₀-Maize+lobia-Wheat+gram (Organic package of practices), T₁₁-Maize + soybean - Wheat + lentil (Organic package of practices), T₁₂- Maize sole - Wheat sole (Organic package of practices) and T₁₃- Maize sole - Wheat sole (Absolute control).
 
Crop management
 
Maize was intercropped with soybean and lobia, respectively. Maize with spacing 60 × 20 cm, soybean and lobia with spacing 45 × 20 cm is recommended for mid hills area for timely sowing. Before sowing of maize, ghanjeevamrit (under natural farming plots) and FYM (under organic farming plots) was applied at the time of final field preparation. Seeds were treated with the beejamrit and biofertilizers as per treatment. Jeevamrit was applied at 14, 21 and 28 days interval in natural farming treatments. Conversely, in the organic farming treatments, matka khad was sprayed at every 30 days interval, respectively. Standard procedures were employed to conduct nutrient analysis of different traditional inputs. Maximum N, P and K content was recorded under ghanjeevamrit (1.25, 0.87 and 0.68%, respectively) followed by beejamrit (0.72, 0.14 and 0.23%, respectively) and jeevemarit (0.25, 0.13 and 0.15 %, respectively).
 
Observations recorded
 
Maize
 
Data on number of plants/m² at maturity, number of cobs/plant, cob length, cob diameter, cob girth, number of grains/cob, test weight (1000- seed weight, grain yield, biological yield (Verma et al., 2015) and maize grain equivalent yield was recorded (MGEY) (Lal and Ray, 1976).
   
Soybean and Lobia
 
Data on yield attributes i.e. plant population at maturity, number of branches per plant, number of pods per plant, number of seeds per pod and test weight as well as yield of soybean and lobia were recorded (Shilpa et al., 2023).
 
Economics
 
Gross returns, net returns and B:C ratio were calculated treatment wise (Shilpa et al., 2023).
 
Statistical analysis
 
The data generated from field and laboratory analysis were subjected to statistical analysis using the technique of analysis of variance for randomized block design for the interpretation of results as described by Gomez and Gomez (1984). The treatment differences were compared at 5 per cent level of significance (P=0.05). Each case was subjected to a standard error of mean calculation. When the ‘F’ value from the analysis of variance tables was significant, a minimum significant difference was calculated.

Yield attributes
 
Different treatments didn¢t have a significant effect on number of cobs per plant and test weight of maize (Table 1) during both the seasons (Kharif 2020 and 2021). In case of cob length, cob diameter and cob girth, treatment T₁ (maize + lobia and jeevamrit spray at 14 days interval) resulted in the highest yield attributes (16.1 cm, 3.87 cm and 15.61 cm) of maize during kharif 2020. However during kharif  2021, treatment T₄ (maize + soybean and jeevamrit spray at 14 days interval) recorded the highest cob length, diameter and girth (15.9 cm, 3.64 and 14.70 cm), while number of grains per cob were found to be maximum (180.1) under T₁ (maize + lobia and jeevamrit spray at 14 days interval) during kharif 2020. However during kharif 2021, significantly higher number of grains per cob (171.8) were recorded under treatment T₄ (maize + soybean and jeevamrit spray at 14 days interval) (Mridula, 2021). Absolute control (T₁₃) resulted in lesser cob length, cob diameter, cob girth and number of grains per cob (133.9 in Kharif 2020 and 110.5 in Kharif 2021) during both the seasons, which might be due to the limited availability of nutrients resulting from the absence of external nutrient sources (either organic or natural). Maize yield attributing characters were significantly improved in treatments where jeevamrit was applied at 14 day intervals (T₄ and T₁) and ghanjeevamrit was added at the time of sowing, which contain small quantities of macro and micro-nutrients as well as growth promoting substances and beneficial microbes (Yadav and Mowade, 2004; Joshi, 2012), which in turn increased the mineralization and solubilization of nutrients in soil, leading to better nutrient availability throughout the cropping season and promoting crop growth and development (Avnimelech, 1986). Mulching was also used to maintain adequate moisture and temperature, which are crucial for balanced metabolic activities of plants and improved soil physical properties, promoting the quick and increased availability of plant nutrients.
 

 
Yield
 
Grain yield was significantly affected by natural and organic farming practices during both the years (Table 2). During kharif 2020, highest grain yield (27.38 q/ha) was obtained under natural farming practices i.e. maize + lobia and jeevamrit spray at 14 days interval (T₁) and it remained statistically at par with the maize + soybean and jeevamrit spray at 14 days interval (T₄) (25.99 q/ha). However, during kharif 2021, significantly higher yield (24.20 q/ha) was obtained in T₄ (maize + soybean and jeevamrit spray at 14 days interval) and it was found to be statistically at par with the treatments T₅ (maize + soybean and jeevamrit spray at 21 days interval) and T₁₁ (maize + soybean and matka khad spray at 30 days interval) (22.88 q/ha and 22.69 q/ha). Whereas, application of jeevamrit at 28 days interval decreased the yield of maize (T₃, T₆ and T₉) in both the seasons, while absolute control (T₁₃) resulted in the lowest yield of maize as compared to natural and organic farming practices during both the seasons.
 

       
The yield of any crop is determined by the assimilatory surface of the plant system, which is influenced by various factors such as plant height, leaf area index and number of leaves. These factors directly affect the distribution of dry matter in different plant parts, ultimately impacting the yield attributes and total yield of the crop. In the present study, maximum grain yield was observed in natural farming treatments T₁ and T₄, which could be attributed to the cumulative effect of ghanjeevamrit at the time of sowing and jeevamrit spray in standing crop and these treatments might have enhanced the microbial activity, leading to increased organic carbon content of soil, which acted as a source of carbon and energy for the microbes. This resulted in the quick buildup of heterotrophic microflora and fauna, leading to better availability of nutrients throughout the crop season and ultimately, positive influence on the growth and yield characters of maize (Thakur, 2022 and Mridula, 2021). Additionally, mulching in natural farming plots played a critical role in conserving soil moisture, controlling weeds and increasing the population of microflora (El-Beltagi et al., 2022).
       
Another reason might be that in an intercropping system (maize + lobia and maize + soybean), part of the nitrogen fixed in root nodules of the legume becomes available to non-legume component (maize). However, there was a decrement in the grain yield of maize in second year of experimentation (2021) by 20.31 % and 6.89 % and 20.08 % and 11.02 % under T₁₀ and T₄ and T₁₀ and T₁₁, respectively as compared to first year. The lower yield observed during the kharif 2021 season can be attributed to the excessive rainfall and high temperatures on maize growth and productivity. High rainfall in the Himalayan region can have detrimental effects on maize yield, particularly in cooler areas with poorly drained soils (Li et al., 2019). Maize is a warm season crop that requires an optimal amount and distribution of rainfall throughout its growing season, making rainfall a critical factor for maize yield. Research has shown that there is a threshold for the amount of rainfall that is beneficial for maize production. While an increase in rainfall can enhance yield up to a certain limit, beyond that point, the additional gain in maize production begins to diminish. Studies by Li et al., (2019); Cudjoe et al., (2021) and Dwamena et al., (2022) have highlighted the detrimental effects of above-normal rainfall on crop yield, including direct physical damage and processes associated with excessive soil water such as waterlogging and flooding, particularly under poor drainage conditions. Excessive waterlogging caused oxygen deficiency in the soil, leading to poor root growth and limited nutrient uptake by maize plants which leads to reduced photosynthetic activity and ultimately decreased yield. In case of maize grain equivalent yield in the year 2020, it was significantly higher (72.53 q/ha) under T₄ (maize + soybean and jeevamrit spray at 14 days interval) followed by T₁₁ (maize + soybean and matka khad spray at 30 days interval) and T₅ (maize + soybean and jeevamrit spray at 21 days interval) (67.13 q/ha and 66.69 q/ha), respectively. Whereas in the year 2021, again T₄ resulted in the highest maize grain equivalent yield (56.52 q/ha) and it was found to be statistically at par with T₁₁ (54.82 q/ha). Higher maize equivalent yield under intercropping system was attributed to yield advantages achieved in intercropping system (Hugar and Palled, 2008). The difference in MEY was mainly as a consequence of differences in the yield of maize, additional component crop yield and price of individual component crops. The use of leguminous intercrops (lobia and soybean) in association with maize could have been responsible for the higher MEY. Leguminous crops are capable of thriving under shade and they have the ability to fix atmospheric nitrogen in the soil, which may have contributed to the increased yield. Furthermore, nutrient competition between maize and intercrops (soybean or lobia) may have been reduced due to different growth habits, thus enhancing the growth and productivity of all the crops involved in the intercropping system. T₃ (maize + lobia + jeevamrit spray at 28 days interval) resulted in the lowest maize grain equivalent yield in both the years (2020 and 2021).
 
Intercrop studies
 
Yield attributes and yield
 
Lobia
 
Treatment T₁ (maize + lobia and jeevamrit spray at 14 days interval) resulted in the highest yield attributing characters (number of branches per plant, number of pods per plant and number of seeds per pod and test weight) of lobia in both the years. In case of plant population at maturity, T₁ during kharif 2020 and T₁₀ during kharif 2021 recorded higher plant population of lobia (Table 3 to 4). Whereas, highest yield (seed and straw) was obtained under treatment maize + lobia and jeevamrit spray at 14 days interval in both the years.
 

 

 
Soybean
 
The treatment maize + soybean and jeevamrit spray at 14 days interval resulted in higher yield attributes (plant population per square meter, number of branches per plant, number of pods per plant and number of seeds per pod) and yield (seed and straw) of soybean during kharif 2020 (Patil and Udmale, 2016; Yadav and Mowade, 2004). Whereas, during kharif 2021, higher values of yield parameters and yield were observed under organic farming treatment maize + soybean and matka khad spray at 30 days interval (Table 5 and Table 6).
 

 

       
The favorable yield attributes of lobia and soybean observed in natural farming plots might be due to mulching which maintained optimal soil moisture and temperature regime, which is critical for the balanced metabolic activities of the plants and resulted in the enhancement of growth characters of lobia and soybean. Moreover under organic farming plots, the increased organic matter content improved soil structure, leading to better distribution of water and nutrients in the soil profile as well as facilitated greater cycling of available nutrients, ultimately enhancing the growth and yield parameters of soybean and lobia (Farooqui et al., 2009). Legumes (Soybean, Lobia), in particular, can serve as effective live mulches due to their ability to suppress weed growth and enhance soil fertility through nitrogen fixation as well as reduce erosion and increase soil moisture retention, ultimately leading to better crop growth and yield. The yield of soybean and lobia decreased in the second season as compared to the first season, which might be attributed to the adverse effects of excessive rainfall on crop growth and productivity by creating an oxygen-deficient environment in the root zone, causing a buildup of carbon dioxide, which negatively affected the crops. The lack of oxygen may disrupt the symbiotic relationship between soybean plants and the Bradyrhizobia bacteria, which are responsible for nitrogen fixation within nodules on the root system (Pampana et al., 2016).
 
Economic studies
 
Economic studies such as cost of cultivation, gross returns, net returns, benefit cost ratio and profitability have been presented in Table 7. T₄ (maize + soybean and jeevamrit spray at 14 days interval) recorded the highest cost of cultivation (49120 ₹/ha and 52220 ₹/ha) during kharif 2020 and 2021, respectively, whereas in case of gross returns, net returns and benefit cost ratio, T₄ (maize + soybean and jeevamrit spray at 14 days interval) was found to be the besttreatment (205252 ₹ /ha, 156132 ₹/ha and 3.18) during kharif 2020 (190040 ₹/ha, 141205 ₹/ha, 2.89 and 187660 ₹ /ha, 139390 ₹/ha, 2.88). T₁₁ was the best economical treatment (163707 ₹/ha, 111822 ₹/ha and 1.73) during second year (Kharif 2021). The variation in the gross returns and net returns was mainly because of the difference in grain and stover yields due to the treatments effect (Table 2). Kasbe et al., (2009) also found that application of jeevamrit with combination of different organic manures was cost effective when used @ 2000 l/ha than when jeevamrit was used alone. It was observed that application of jeevamrit in combination with other organic manures such as vermi-compost is one of the cheapest and most effective organic sources in an integrated approach for high crop yield and profitability. However, lowest net returns (27700 ₹/ha and 12446 ₹/ha) were recorded under T₉ (maize sole and jeevamrit spray at 28 days interval) in 2020 and under T₁₃ (absolute control) in 2021, which was the result of lower grain and stover yields as compared to cost of cultivation (Kumar, 2015). Lowest lowest benefit cost ratio was obtained under T₉ (maize sole and jeevamrit spray at 28 days interval) during both the years (0.71 and 0.37), might be due to high cost of cultivation as compared to grain and stover yield, which provided lesser profit (Singh et al., 2008).
 

In present scenario, where there is destruction in soil and plant health, it is important to adopt a sustainable cropping system which should be environmental friendly and economically sound. In the present study, emphasis was given on the use of organic nutrient sources and it was concluded that maize intercropped with lobia or soybean along with application of jeevamrit at 14 days interval proved to be the best treatment for enhancing the crop productivity. However, in terms of economic benefits (gross returns, net returns and benefit: cost), both the farming practices showed promising outcomes, suggesting that they can be effective agricultural approaches for sustainable and economical crop production.

The authors declare no competing interest.