Growth attributes
Plant height (cm)
Plant height up to 90 DAS increased gradually regardless of treatment effects and then remained steady till maturity. During both cropping seasons, T
10 showed the greatest increase in plant height compared to the other treatment combinations. However, it varied significantly with the INM treatments where in T
10 (100% RDF+FYM+
Azospirillum lipoferum+PSB+KMB+
Glomus+ZnSB) showed the highest growth (Fig 1). However, plant height did not vary between 1st and 2nd year cropping.
The integration of nutrients could assist the crop acquire better nutrition, minimizing N loss and prolonging its availability to the rice plant, as well as improving plant height
(Kashyap et al., 2017). Plant height is increased by chemical fertilizer, organic manure plus bio-fertilizers due to increased nutrient availability driven by the solubilization effect and microbial decomposition
(Wailare and Kesarwani, 2017). Furthermore, FYM supplemented the soil with significant amounts of NPK, as well as other macro and micronutrients required for plant growth. However, because of the sluggish release of nutrients, all plant height was lowered in the organic treatment compared to the conventional treatment, as reported by
(Sharma et al., 2018).
Number of tillers hill-1
The number of tillers hill
-1 started to propagate at 45 DAS and indicated a linear increase up to 60 DAS. It was the greatest in INM treatments (T
10), followed by sole use of chemical fertilization and organic fertilization and this might be due to more supply of nutrients during growth stages. INM treatments influenced number of tillers hill
-1 significantly (p<0.05) in both the cropping years, but the treatment wise effect was similar between the cropping years (Fig 2).
The INM treatment (T
10) might have increased the nutrient content in rice plants at the tillering stage, leading to a significant increase in the number of tillers hill
-1 at 60 days. Besides tillering, INM improves crop nutrition too by reducing N loss and increasing N availability to rice plants
(Choudhary et al., 2007). After 60 days, there were fewer tillers, which was likely due to ageing and senescence, which caused the secondary and tertiary tillers to die
(Singh et al., 2018). The number of tillers hill
-1 was lower in the organic and bio-fertilizer treatments compared to the chemical treatment
(Sharma et al., 2018). FYM application produced more tillers as compared to treatments without FYM that had the same NPK levels. The conventional approach combined with FYM and bio-fertilizers may result in maximum tiller counts than chemical fertilizers or organic alone
(Kumar et al., 2012). Fig 2 shows a significant difference among treatments and cropping year but the interaction between them had a non-significant effect on number of tillers hill-1.
Number of panicles tiller-1
The number of panicles climbed steadily as fertility levels rose as a result of better crop nutrition (Table 1). This eventually led to a steady increase in grain and straw yields of rice. Rice panicles grew consistently with fertility levels when plants received higher nourishment
(Choudhary and Suri, 2014). Similar to observation by
(Borah et al., 2016) crop receiving INM produced higher number of panicles than those obtained with the other treatments (during both the years), whereas the lowest was recorded with control. Slow release and continuous supply of nutrients in balanced amounts during different growth phases, ensured by the application of organic and conventional fertilizers led to the production of more panicles with more fertile grains and promoted better plant growth
(Singh et al., 2018).
Panicle length
Compared to control, panicle length significantly increased with different fertilizer treatments. During both years, crops receiving INM treatments generated longer panicles than those obtained with other treatments. Panicle length rose in a consistent manner as fertility levels improved with greater nutrition for rice plants, showing the largest magnitude in plots fed with INM and the lowest in those using only NPK (Table 1).
Using organic with chemical fertilizers increased the effectiveness of native and applied nutrients being utilised at a faster rate, favouring panicle length
(Sharma et al., 2018). When compared to each counterpart treatment with the identical NPK levels, FYM resulted in the longest panicle length. FYM may have provided essential minerals and influenced the efficient utilization of applied nutrients to lengthen panicles
(Singh et al., 2018).
Number of grains panicle-1
Maximum number of grains panicle
-1 was produced by application of RDF + FYM + bio-fertilizers (T
10), over other treatments during both the cropping years. Higher grains panicle
-1 were recorded with INM treatments and also in RDF; the lowest was recorded in control. Number of grains panicle-1 resulted from INM and chemical treatments were at par (Fig 3).
The fertility level in (T
10) improved plant nutrition, hence, the filled grains panicle
-1 grew constantly, leading to steady increases in rice yields
(Choudhary et al., 2007). Combining organic and chemical fertilizers helps to provide all of the balanced and high-quality nutrients throughout the growing season, allowing rice plants to assimilate enough photosynthetic products and produce more viable grains
(Singh et al., 2018).
Solitary application of chemical, organic, or bio-fertilizers was found to be less effective in raising the number of panicles tiller
-1, in improving the panicle length and in raising the number of grains panicle
-1 of upland rice
(Borah et al., 2016), as it inhibits the inability to give plant the needed nutrients in accordance with the crop’s demand, as also reported by
(Sharma et al., 2018).
Test weight (g)
Fertility treatments significantly raised test weight compared to the unfertilized plots. INM treatments received the most weight. During both the cropping years, the test weight (1000-grain weight) varied from 24.07 to 27.03 g. The sequence in which different treatments had an impact on the weight of 1000 seeds was T
10>T
3>T
9>T
5>T
4>T
7>T
8>T
6> T
2>T
12>T
11>T
1 (Fig 4).
According to
(Subramani et al., 2005), test weight is rather stable and does not vary noticeably among methods for nutrient fertility management (Fig 4). Higher plant nutrition for rice plants led to constant increase in 1000-grain weight with increasing fertility levels, with the largest increase occurring in plots supplied with organic and inorganic fertilizer. During the various growth phases, nutrients required by the crop are continuously supplied in a balanced quantity, so it enable the plant to digest sufficient photosynthetic products, resulting in increased test weight
(Singh et al., 2018). Control plots reported the lowest 1000-seed weight as it was devoid of any nutrient application.
The study reveals that all the growth parameters except test weight showed significant variation among the treatments and between the cropping years. Growth variables also increased significantly from 1
st year to 2
nd year cropping. However, initially plant height did not vary between the cropping years till 60 DAS but induced a significant variation among treatments throughout the growing period, thereafter it showed significant enhancement in height growth in 2
nd year crops compared to 1
st year crops.
Yield attributes
Grain and straw yield
The highest grain and straw yield were recorded in the INM plots (T
10) (Table 2) during both the years. Better yield attributes accrued from the integrated use of fertilizers resulted in the highest grain and straw yield of upland rice which was, however, statistically at par with treatments applied.
Compared to solitary fertilizer application,
(Sharma et al., 2018) found that INM treatments produced the maximum grain and straw yield. Furthermore, under the impact of better physical and chemical soil features, INM plots absorb more nutrients, resulting in increased yield
(Tripathi et al., 2013).
Rice yield improved in RDF plots and they improved more when organic sources were substituted
(Padbhushan et al., 2021; Singh et al., 2018). (Sowmya et al., 2011) also stated that integrated nutrient management, is necessary for long-term output. Organic manure’s improved effect on grain and straw yields could be attributed to a more consistent supply of plant nutrients
(Aruna and Mohammad, 2011; Kumar et al., 2018). Also, when chemical fertilizers and bio-fertilizers were combined, the yield was higher than when organic fertilization were used alone, emphasising the importance of INM to achieve higher production
(Kumar et al., 2018). Because of poor and fragile upland soils, control plots yielded the lowest grain and straw yield (Table 2).
Grain yield did not vary with treatments, but showed a significant variation between the cropping years. However, straw yield was significantly (P<0.05) higher in T
10, but shows a non-significant variation between the cropping years. On the other hand, the grain yield increased from 1
st year to 2
nd year crops in all the treatments. Straw yield, however was at par between the two cropping years.
Economics
HI and BCR were recorded the maximum in T
10 (100 % RDF + FYM +
Azospirillum lipoferum + PSB + KMB +
Glomus + ZnSB) in 1st year cropping. On the other hand T
9 (100% RDF +
Azospirillum lipoferum + PSB + KMB +
Glomus + ZnSB) showed maximum value of HI and BCR in 2
nd year crops. However, the economic parameters increased from 1
st year to 2
nd year cropping irrespective of treatments applied (Table 3).
Since fertility practices had a similar impact on grain and straw yields, nutrient management had no impact on HI
(Borah et al., 2016). Furthermost, the cost benefit analysis of the present study shows that T
10 and T
9 under improved nutrient management gave the highest BCR. Similar findings was also reported by
(Srinivasarao et al., 2020). Both grain and straw yield did not vary with various treatments, but showed a significant increase in the second year of cropping.
