Investigating The Influence of Temporal Dynamics and Nutrient Levels on Soil Health, Plant Uptake and Yield Attributes of Toria in the Trans-gangetic Region of Punjab Towards Sustainable Development Goals

Indian mustard (Brassica sp.) is an important oilseed crop in the Cruciferae family. Rapeseed and mustard are two major categories for Indian mustard (Jadhav and Jadhav, 2021). Oilseeds are India’s second most important agricultural commodity after wheat (Shehzad et al., 2023). The rapid increase in population has increased the demand for oilseed crops because they are used in various forms in our ecosystem and the reason for the lesser production of oilseed crops is lack of knowledge and resources which is required for cultivation of oilseeds. Hence, it is important to enhance the production by obtaining maximum knowledge about the cultivation (Rai et al., 2022).
       
At present, the major obstacle in the cultivation of toria is the quality and quantity of produce. Fluctuations in the dates of sowing led to fluctuation in thermic environments of different cultivars which changes the growing and developmental stages of the plant and leads to modifications in the life cycle of plants (Kumar and Meena, 2020). Seasonal variations, including fluctuations in temperature, precipitation and seasonal timing, significantly impact crop phenology, growth phases and overall output. These temporal fluctuations can modify the essential growth phases of toria, resulting in variability in productivity during growing seasons. Nutrient imbalances-resulting from excessive or insufficient fertilizer applications-negatively impact soil health, plant nutrient absorption and total crop yield. Extended nutrient mismanagement diminishes production and degrades produce quality, hence challenging sustainable agricultural techniques.
       
Modern agronomic techniques, including excessive use of chemical fertilizers and a restricted emphasis on soil amendments, along with fluctuating climatic variables such as erratic climate patterns, are compromising the yield potential of toria. These actions require a shift to more balanced and adaptive nutrient management systems.
       
The major factors which regulate the production of any crop are its genes, environmental factors and nutrition. We can’t change its genes, but we can provide excellent growing environment and nutrition so that we get maximum output from the crop. Nitrogen is the most essential nutrient responsible for the crop’s growth, yield and oil and protein content. Phosphorus is also readily used in nitrogen availability. It also aids in blossoming, siliqua setting and siliqua elongation (Dubey et al., 2021). Just after nitrogen, potassium plays a key role in influencing performance and productivity of production by enhancing photosynthetic activities (Rana et al., 2021 and Chandranath et al., 2020). To find the best nutrient levels and favorable dates for sowing. We chose three different dates and four different nutrient levels to evaluate the response of toria under different temporal dynamics in combination with different nutrient levels.

The investigation was conducted during the rabi season in 2021-22 and 2022-23 at Agricultural Farm of Lovely Professional University, Phagwara, Punjab, India. The experiment was laid out in factorial RBD design with three sowing dates, D1 (1^st October), D2 (15^th October) and D3 (30^th October) and four distinct fertilizer levels, 75%RDF, 100% RDF, 125% RDF and 150% RDF. 12 treatment combinations of dates of sowing and fertilizer levels were replicated three times. The total number of plots were 36 in numbers with plot size of 5x3 m and row spacing 45 cm and plant-to-plant distance 10 cm. The soil of the experimental site was sandy loam in nature. The analysis of soil was done before the start of the experiment to evaluate the initial status of the soil. To procure an optimum yield 60 kg N, 40 kg P, 30 kg K and 30 kg S ha^-1 applied. Nitrogen is given in split doses; P and S are applied during land preparation as basal doses. The PAU recommended variety TL-17 of Toria had been selected as planting material for the experiment.
 
Yield attributes and yield parameters
 
The number of siliqua per plant was counted by removing the 3 tagged plants and recorded the mean values.10 randomly chosen siliqua was plucked from the plant’s shoot and measured in cm using a cm-scale. After threshing, a seed counter counted 1000 seeds, which were weighted by an atom weighing machine and the average value computed. The crop was harvested from net plot and threshed. The value was multiplied by 10,000 to get values per hectare. The harvest index was calculated using the Donald,1976 formula and recorded.
 
Properties of soil on the experimental site
 
Before sowing, all plots were augured 15-20 cm deep for soil samples. The experimental location is sandy loamy with 78% sand, 8% silt and 14% clay. The soil was alkaline (8.2), EC (0.26 dSm^-1), medium organic carbon (0.42%), medium available N (340 kgha^-1), K (321 kgha^-1), high available P (20 kgha^-1) and low available S (5.6 kgha^-1). pH and EC meters measured soil pH and EC (Jackson,1973). Wet digestion method was used to measure organic carbon (Walkley and Black 1934). Available nitrogen, P, K and S were measured using Alkaline permanganate, Olsen, Neutral normal ammonium acetate and Turbidimetric methods, respectively.
 
Uptake and concentration of nutrients
 
At toria maturity, the concentrations of nitrogen, phosphorus, potassium and sulfur in stover were estimated. The samples were powdered in Willey’s mill to pass through a 30-mesh screen after being oven-dried at 65-70oC. Nitrogen was determined using the Micro-Kjeldahl method (Bremner, 1960), phosphorus was measured by the Vanadate Molybdate method using a colorimeter/spectrophotometer, potassium was analyzed through Flame Photometry (Jackson, 1973) and sulfur estimation followed the method described by (Palasker et al., 1981).
 

 

  
Statistical analysis
 
The recorded pooled data of 2 years was tabulated treatment-wise under three replications. The generalized linear model estimated the differences between the mean values under full factorial univariate techniques with SPSS 22 version. To find out the most efficient treatment, Duncan’s multiple range test (DMRT) was employed. A mean separation technique was applied with a probability of p<0.05. Fisher’s LSD test as a post hoc test was used to test the significance of the various components.

The impact of various dates of sowing and different nutrient levels on the yield attributes
 
In both years, 1^st DOS and 100% RDF produced more siliqua per plant (208). Table 1 reveals that 3^rd DOS with 75% RDF had the lowest plant siliqua (139.33). Enough nutrients and peak planting time improved photosynthetic accumulation and reproductive duration. Vegetative development and reproduction at the ideal temperature may increase yield. The findings support Sau et al., (2022) and Jadhav and Jadhav (2021) who concluded that using 75% of RDF from chemical fertilizers along with FYM at a dose of 5t/ha in combination with Azotobacter improved growth and productivity in toria crops grown in the trans-Gangetic plains of Punjab. 1^st DOS and 100% RDF yielded the longest siliqua (4.8 cm). Siliqua has the shortest average length (3.02 cm) in 3^rd DOS and 125% RDF. Weather and nutrition greatly impact yield. Environmental factors promote abiotic restrictions. Abiotic stresses affects physiological, morphological, biochemical and molecular changes that may affect plant reproduction and yield variables like average siliqua length, seeds per siliqua and test weight. Chaudhary et al., (2023) results corroborate with the findings of this result who conclude that significantly higher yield attributes viz. siliquae plant^-1, seed per siliquae, siliqua length and 1000 seed weight recorded with early sown crop. Crop sown on 26^th October recorded 27% and 40% higher seed yield than 5^th and 15^th November sown crop, respectively. Similarly, the percent increase in stover yield was 27% and 29% in 26^th October sown crop over 5^th and 15^th November sown crop respectively, though the difference between the late sown crops remained comparable. Interaction effects of planting dates and fertilizer doses showed the highest siliqua (16) in 1^st DOS and 100% RDF and the lowest (12) in 3^rd DOS x 75% RDF, statistically comparable to 1^st DOS x 75% RDF and 3^rd DOS x 125% RDF. A balanced diet enhances cell elongation/division, photosynthetic activity and physiological activity, which boosts yield. Sharma and Kumar 2023 found similar results. Planting dates and fertilizer levels produced the highest test weight (4.33 g) in the 100% RDF and 1^st DOS interaction. Conversely, the 75% RDF x 3^rd DOS interaction had the lowest test weight (3.33g). Due to nutrients and planting time, chlorophyll content increased. Ideal temperatures boosted vegetative growth and reproduction, which may increase test weight. Similar results were found by Tripathi et al., (2021) and Kour et al., (2016) who reported that highest growth attributes (plant height, dry matter accumulation, Days taken to 50% flowering, number of tillers, LAI and yield and yield attributes (No. of siliqua (cm) per plant, length of siliqua (cm) test weight, seed yield (q/ha) grain yield, stover yield, biological yield and harvest index) was recorded under 1^st week of october in varuna variety. DOS with 100% RDF produced the more seeds (1255 kg ha^-1) and was statistically superior to all other combinations. However, 75% RDF and 3^rd DOS produced the less seeds (790 kg ha^-1). The crop sown on the right date had an expanded reproductive phase under optimal climatic circumstances with ample nutrients, resulting in a better seed set, larger siliquae and maximal potential growth, which may have increased seed output. Jadhav and Jadhav (2021) found similar results. A combination of fertilizer levels and planting dates led to the highest stover yield (2314.66 kg ha^-1) with the 1^st DOS x 100% RDF level, outperforming other combinations. However, 150% RDF with 3^rd DOS produced the least stover (1951.66 kg ha^-1).   

                   

The 2^nd and 3^rd DOS crop may have experienced unfavorable climatic circumstances like temperature and moisture stress that hindered nutrient uptake and created stress in the plants, resulting in poor plant growth, a quick stover production reduction in delayed sowing and misbalanced nutrition in toria. Sharma et al., (2020) and Anuroop (2022) reported similar results as per late sowing in their regions and balancing fertilizer doses increase the production of Toria. Due to fertilizer amounts and planting dates, 1^st DOS and 100% RDF yielded the highest HI (40.67%). Maurya et al., (2022) reported comparable results who reported that NRCHB-101 variety of toria shows better performance in terms of growth as compared to variety PM-28 during Ist week of October.
 
The impact of various dates of sowing and different nutrient levels on the uptake and concentration in stover
 
Planting dates greatly affects stover nitrogen absorption and concentration. The first DOS-sown plants had the highest nitrogen (2.47%). Plants grown on 3rd DOS had the lowest nitrogen (2.06%). Stover N uptake was highest in the first DOS crop (55.68 kg ha^-1). Table 2 reveals the 3rd DOS crop had the lowest stover N uptake (41.08 kg ha^-1). Fertilizer levels affects stover nitrogen absorption and concentration. 100% RDF had the highest stover nitrogen (2.47%). The lowest nitrogen concentration was 2.02% in 75% RDF stover. Different fertilizer amounts and sowing dates had minimal effect on stover nitrogen level. The first DOS-sown plants had the highest phosphorus (0.259%). The lowest phosphorus concentration (0.182%) was in 3^rd DOS plants. However, 1^st DOS plants absorbed the most stover phosphorus (5.81kg ha^-1) and 3^rd DOS plants the least (3.61kg ha^-1). Different fertilizer doses influenced stover phosphorus uptake and concentration. Stover phosphorus was highest (0.257%) with 100% RDF and similar (0.226%) at 125% RDF. Stover with 75% RDF has the lowest phosphorus (0.169%). The highest stover phosphorus uptake was 5.70 kg ha^-1 for plants fertilized with 100% RDF, whereas the lowest was 3.53 kg ha^-1 for plants fertilized with 75% RDF. Stover phosphorus uptake was unaffected by sowing date or fertilizer amount. The 1^st DOS harvest has the most stover potassium (2.66%). The crop grown on 3rd DOS had the lowest stover potassium concentration (2.13%). The highest stover potassium uptake was found in 1st DOS plants (60.05 kg ha^-1) and the lowest in 3^rd DOS plants (42.48 kg ha^-1). Stover potassium absorption varied with fertilizer dosage.100% RDF amendment had the highest stover potassium (2.64%). Stover potassium was lowest at 75% RDF (2.01%). The highest stover potassium uptake (58.81 kg ha^-1) was with 100% RDF, while the lowest was 42.12 kg ha^-1 with 75%. Stover potassium uptake depends on sowing date and fertilizer. Stover potassium content reached at 3.23% in the first DOS x 100% RDF interaction. Lowest potassium content (1.89%) in stover was found at 3^rd DOS x 75% RDF level. Stover potassium uptake was highest (74.80 kg ha^-1) with 1^st DOS and 100% RDF. In the 3^rd DOS x 75% RDF interaction in stover, the minimum potassium uptake was 37.45 kg ha^-1. The 1st DOS harvest had the greatest stover potassium (0.437%). Third DOS plants had 0.314% stover sulfur. The largest stover sulfur uptake (9.86 kg ha^-1) was on 1^st DOS and the lowest (6.23 kg ha^-1) on 3^rd DOS. Stover sulfur absorption varied with fertilizer dosage. The highest stover sulfur (0.460%) was with 100% RDF. 100% RDF has the highest stover sulfur uptake (10.26 kg ha^-1). The stover uptake of sulfur was lowest at 75% RDF (6.36 kg ha^-1). Sowing dates and fertilizer levels affects stover sulfur uptake. When paired with 1^st DOS (1 October) and 100% RDF, stover sulfur content reached at 0.573 per cent. The stover sulfur level was lowest (0.277%) in the 3^rd DOS x 75% RDF interaction. Ist DOS and 100% RDF caused stover sulfur uptake to be greatest (13.26 kg ha^-1). The 3^rd DOS x 75% RDF interaction led to the lowest stover sulfur uptake (5.45 kg ha^-1). Maximum stover NPKS uptake with 100% RDF may be due to balanced diet and fertility. If dosed properly, all nutrients interact and increase absorption. These findings corroborate with the findings of Kumar et al., (2020) who reported that higher fertiliser doses may raise soil pH and disrupt fertiliser interaction, reducing nutrient uptake. Nutrient concentration in plant samples improves with balanced fertilizer doses, which may explain why balanced and recommended fertilizer doses generate the maximum NPKS concentration. Kumar et al., (2021) and Dubey found similar results which conclude that among the nutrient sources application of 75% RDF+ 25% N through PM +Azotobacter + PSB maximum total nitrogen, phosphorus, potassium and sulphur uptake was recorded as compared with other nutrient sources.

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Available NPKS in the soil after harvest
 
The 3rd DOS had the highest soil N (280.33 kg ha^-1). The 1st DOS had the least N (261.66 kg ha^-1). The first DOS had the greatest soil phosphorus (21.95 kg ha^-1). Table 3 demonstrates that the 3^rd DOS had the lowest soil phosphorus (19 kg ha^-1). Ist DOS soil potassium was highest (312.16 kg ha^-1). 3^rd DOS had lowest soil potassium and was statistically similar to 2^nd DOS. Different nutrient levels affects soil NPK. The 150% RDF yielded the greatest N (291.22 kg ha^-1). Nitrogen was lowest at 75% RDF (250.77 kg ha^-1). Phosphorus was highest at 150% RDF (22.44 kg ha^-1). The least phosphorus (18.50 kg ha^-1) was observed in 75% RDF, which was statistically equal to 100% and 125%. The highest soil potassium (323.33 kg ha^-1) has 150% RDF. Fertilizer quantities and sowing dates affected nitrogen and potassium levels but not phosphorus. The 3^rd DOS and 150% RDF interaction produced the most soil nitrogen (304.66 kg ha^-1). Minimum soil N (244.66 kg ha^-1) was found in the 2^nd DOS x 75% RDF interaction. However, 2^nd DOS and 150% RDF interlinkage produced the most soil phosphorus (23.16 kg ha^-1). Low soil phosphorus (17.16 kg ha-1) was observed in the 2^nd DOS x 75% RDF interaction. The 1^st DOS x 150% RDF interaction had the most soil potassium (328.66 kg ha^-1). 3^rd DOS had the greatest soil sulfur (6.42 kg ha^-1) and was statistically comparable to 2^nd DOS. The lowest soil sulfur was 6.21 kg ha^-1 in 1^st DOS. Fertilizer levels affected soil sulfur. The maximum soil sulfur (6.61 kg ha^-1) was calculated with 100% RDF and statistically similar with 125% RDF. Soil sulfur was lowest at 75% RDF (5.82 kg ha^-1). Fertilizer and sowing dates altered soil sulfur. Maximum soil sulfur (7.30 kg ha^-1) was observed in the 2^nd DOS x 125% RDF interaction. In contrast, the 3^rd DOS x 75% RDF interaction yielded the lowest soil sulfur (5.73 kg ha^-1). Overfertilization can harm soil. Nutritional boosts defect toria oil. Similar results were observed by Bora et al., (2021) who conclude that overfertilization raises soil salinity, which may affect plant development and microbial activity. Mukherjee 2020 and Mishra et al., (2022) reported similar results who conclude that integration of inorganic fertilizer both macro and micro with organic manure and biofertilizer is the better option for balance nutrition of the rapeseed mustard crop that enriches the soil fertility status, improves growth and yield attributes of crop and also accelerates the nutrient uptake and availability in soil and ultimately the productivity and profitability and quality of food.

The study found that toria (Brassica campestris var Toria) benefited from planting on the 1^st DOS (1^st October) in terms of siliqua per plant, length of siliqua, seeds per siliqua, seed yield, nutrient uptake, concentration and soil nutrient availability. This suggests that the 1^st October is the optimal date for sowing for optimal growth and development. During the experiment period late September in Punjab experienced residual heat from the monsoon. Sowing on 1^st October might ensure slightly cooler temperatures, reducing heat stress during germination and early vegetative growth. Changes in monsoon patterns might have shifted the ideal moisture availability to early October, making it favorable for seed germination and crop establishment. For photoperiod-sensitive crops like mustard, a slight delay in sowing may align with cooler nights and shorter days in October, promoting optimal vegetative and reproductive development. Thus, yield and nutrient availability are optimum with 100% RDF. The research found that the interaction between 1^st DOS (1^st October) and 100% RDF was the most effective treatment.

The present study was supported by Lovely Professional University, Phagwara.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
 
Informed consent
 
All animal procedures for experiments were approved by the Committee of Experimental Animal care and handling techniques were approved by the University of Animal Care Committee.

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.