Yield performance
Over three seasons 2019-20, 2020-21 and 2021-22 and five locations, the cotton-redgram intercropping system in a 6:1 row ratio consistently outperformed sole cotton. The system maintained a uniform and robust plant stand, with about 15,357 cotton plants and 2,527 redgram plants per hectare. This configuration delivered a mean system yield of 2031 kg ha
-1, comprising 1537 kg ha
-1 from cotton and 494 kg ha
-1 from redgram, compared with 1690 kg ha
-1 under sole cotton (Table 2). The yield advantage reflects the complementary roles of the two crops: redgram fixes atmospheric nitrogen, improves soil physical conditions and helps buffer the microclimate within the canopy, which together support better boll retention and higher biomass in cotton.
These yield gains were also closely linked to the systematic use of Agro meteorological Advisory Services (AAS) throughout the study period. Location-specific weather-based advisories on sowing dates, irrigation scheduling, nutrient application and plant protection enabled farmers to time operations more precisely with short-and medium-range forecasts, lowering exposure to weather-related risks. Similar positive impacts of AAS on yields, income stability and risk reduction have been documented in other agro-climatic regions
(Rakesh et al., 2025) and are consistent with national assessments of the strengthened GKMS/AAS framework
(Rathore et al., 2025) and evidence that village-level agromet display boards and advisories promote adoption of weather-informed decisions
(Roy et al., 2025).
Resource-use efficiency
Intercropping also clearly improved how land and inputs were used. The cotton–redgram system recorded a mean Land Equivalent Ratio (LER) of 1.30 and a mean Cotton Equivalent Yield (CEY) of 1993 kg ha
-1, representing roughly 15% higher productivity compared with sole cotton. An LER above 1.0 indicates that the intercropping system uses light, water and nutrients more efficiently per unit area than when crops are grown alone. This pattern agrees with findings from other cotton-based intercropping systems, including cotton-pigeonpea, where LER values typically exceed 1.0 and CEY is substantially higher under intercropping (Table 2).
Latheef et al. (2018) gains better yield and economic returns through complementary canopy structures and more efficient resource use.
Our results are further supported by broader multicropping literature showing that intercropping tends to enhance both resource-use efficiency and overall system productivity.
Gao et al. (2023), for instance, used MANOVA in daylily-based intercropping trials to demonstrate multivariate gains in yield and associated traits. While
Huang et al. (2022) show that tea-legume intercropping improves nitrogen availability, soil organic matter and microbial activity, thereby enhancing overall resource-use efficiency. By biologically fixing nitrogen and improving nutrient cycling, legumes reduce fertilizer dependence and allow tea plants to use soil resources more effectively.
Economics
Economically, cotton-redgram intercropping proved clearly superior to sole cotton. The mean cost of cultivation under intercropping was lower (₹ 50,284 ha
-1) than under sole cropping (₹ 52,262 ha
-1), yet the system generated higher gross returns (₹ 117,069 ha
-1) and net returns (₹ 66,434 ha
-1) (Table 3 and 4). As a result, the Benefit-cost ratio (BCR) under intercropping was 2.30, compared with 1.71 for sole cotton, indicating that each rupee invested in the intercropped system yielded substantially higher returns. The additional grain yield from redgram, more efficient use of shared inputs and operations and the spreading of risk across two crops all contributed to this economic advantage.
These outcomes also illustrate why intercropping should be evaluated using multi-trait criteria that combine yield and economic metrics rather than yield alone. Recent reviews on new statistical approaches for intercropping experiments have encouraged the use of multivariate tools such as MANOVA and discriminant analysis to capture integrated yield-income responses. In line with this perspective, our results corroborate earlier reports by
Pandagale et al. (2019), which showed that cotton-legume intercropping not only increases profitability but also enhances economic resilience compared with mono-cropped cotton.
Multivariate statistical validation
Multivariate diagnostics and MANOVA
Before applying multivariate models, we assessed whether the data met key statistical assumptions. Royston’s multivariate normality test was non-significant (p = 0.473 > 0.05), indicating that the joint distribution of the response variables did not deviate significantly from multivariate normality and was suitable for both MANOVA and LDA. A similar diagnostic strategy was followed in the Brazilian study “Selection of Indicators to Discriminate Soil Tillage Systems”
(Kazmierczak et al., 2020) where Shapiro–Wilk and Royston’s tests were applied prior to discriminant analysis, underscoring the importance of careful assumption checking in agronomic datasets.
In our study, MANOVA results (Table 5) a highly significant effect of cropping system (Wilks’ Λ = 0.2693), with the model explaining 73% of the total multivariate variance. Among the response variables, yield was the dominant contributor (65.9%, p<0.01), followed by cultivation cost, net returns and gross returns, while BCR made a comparatively minor and non-significant contribution. The Univariate ANOVA also results represented that the treatments clearly influenced NR, CC, GR and especially yield, as all of these traits show strong statistical significance. However, BCR did not respond much to the treatments, indicating that it remained relatively unaffected compared to the other traits.
Discriminant analysis and system separation
Linear Discriminant Analysis (LDA) provided additional insight into how well the two cropping systems could be separated using the measured variables. The first discriminant function was:
The large negative coefficient for yield indicates that higher yields strongly pulled LD scores toward the intercropping system, highlighting yield as the main driver favouring that system. In contrast, positive coefficients for BCR and cultivation cost shifted scores toward sole cropping, indicating that these traits, when considered jointly with others, tended to characterize the mono-cropped fields. Mean LD scores clearly distinguished the two groups (Intercropping = -1.3; Sole = +0.64 showed Fig 1) and the model achieved 100% correct classification showed in Fig 2, demonstrating very strong multivariate separation between the systems in different representation.
Comparable discriminant or Linear Discriminant Analysis Effect Size (LEfSe) type analyses have been used in agronomic and ecological studies to differentiate treatments or management systems
(Gao et al., 2023) and our findings are in line with these reports. In all cases, discriminant analysis helps reveal which traits or combinations of traits which most strongly contribute to group separation.
Integrated interpretation and implications
Overall, the combination of field performance and multivariate statistics makes a strong case for cotton-red gram intercropping as a superior alternative to sole cotton. The system delivers higher yields, better economic returns and more efficient use of land and inputs, while also satisfying key statistical model assumptions and showing clear multivariate separation from mono-cropping. These features echo earlier work on the multivariate stability and discriminant potential of diversified cropping systems
(Gao et al., 2023).
The simultaneous improvements in yield, reduced cultivation costs and complementary use of light, water and nutrients position intercropping as both economically attractive and ecologically sound. This aligns with foundational intercropping concepts proposed by
Raseduzzaman and Jensen (2017), who emphasized the potential of mixed cropping to increase overall system efficiency. In the present context, cotton-redgram intercropping, especially when supported by robust AAS-based management, emerges as a practical pathway towards sustainable intensification under variable and changing climatic conditions.