Impact of Different Rice Straw Management Techniques and Nitrogen Levels on Yield and Nutrient Uptake in Wheat (Triticum aestivum L.)

Wheat is one of the world’s most important staple food crops that has been labelled as King of Cereals It contributes 24% in the total foodgrain production in the country, next to rice. It is grown in 31.8 million ha in India with the production of 113.9 million tonnes and productivity of 3.6 tonnes/ha (Ministry of Agriculture and Farmers Welfare, 2024).
       
Once dismissed as wastes, crop residues are now valued as potential black gold for their nutrient-rich content that boosts agricultural productivity (Reicosky and Wilts, 2005). In India, significant crops like rice, wheat, maize and sugarcane generate around 686 million tonnes of residues annually, with cereals being the largest contributors followed by sugarcane (56 MT) and others (47 MT) (Ministry of Agriculture and Farmers Welfare, 2020). Effective management of these residues is becoming increasingly important amid rising environmental concerns about chemical inputs in agriculture (Dadhich et al., 2021).
       
Rice straw, a widely available agricultural by product, represents one of the most abundant lignocellulosic wastes in the world (Saini et al., 2013). Given that rice is a staple food for over half of the global population, particularly in Asia, this resource is particularly significant (Singh and Arya, 2021). Other crop residues, such as pearl millet husk, groundnut shell and sesame stover, often go to waste due to their high carbon-to-nitrogen (C/N) ratios and lack of use as animal feed (Vaswani et. al., 2013). Unfortunately, ineffective management leads to these residues being burned in fields, causing environmental pollution and depleting essential soil nutrients (Goyal et al., 2009).
               
Therefore, integrating crop residues with inorganic fertilizers represents a powerful strategy for enhancing soil health and boosting long-term crop productivity. This holistic approach not only maintains crop yields but also improves nutrient use efficiency and enriches soil fertility. By leveraging the synergy between these resources, we pave the way for a more sustainable agricultural future that maximizes the benefits of our natural assets.

Experimental site
 
The research trial was conducted during Rabi season of 2022-23 and 2023-2024 at the experimental farm of Department of Agronomy, School of Agriculture, Lovely Professional University in Phagwara, Punjab, India. The farm is situated at 31^o14'35.2" North latitude and 75^o41'48.2" East longitude in a semi-arid, subtropical climate with 245 m average elevation from above mean sea level. Most of the annual rainfall (500-800 mm) occurred during the monsoon season, between July to September, with groundwater found at depths of 90-100 meters.
 
Experimental details and crop management
 
The study conducted during rabi 2022-2023 and 2023-2024 assessed the impact of different rice straw management techniques and nitrogen levels on wheat yield and quality. A split-plot design with 12 treatment combinations, replicated three times across 36 plots, was used to evaluate two main factors: The two key factors tested were: in main plot Rice Straw Management: S₀: (conventional sowing) S₁: (Sowing with super seeder) S₂: (Straw decomposed using Pusa bio decomposer) in sub plot Nitrogen levels: N₀: (Control) N₁: (75% RDN), N₂:(100% RDN), N₃: (125% RDN). Rice straw decomposed with the Pusa bio decomposer was incorporated into designated plots before sowing. The straw underwent microbial decomposition for 20 days to enhance nutrient availability.
       
The wheat variety PBW 824 was sown using the drilling method. Data collection included measurements of crop growth, biomass, grain yield and nutrient uptake along with soil nutrient content and organic carbon levels. Pre- and post-treatment soil samples were analysed for nitrogen, phosphorus and potassium levels.
       
The soil, characterized as sandy loam from the Central alluvial plain, exhibited a pH of 7.6 and an electrical conductivity (EC) of 0.47ds/m. Initial tests conducted in October 2022 revealed moderate organic carbon content (0.57%) alongside low concentrations of essential nutrients, including nitrogen (183.7 Kg/ha), phosphorus (26.4 Kg/ha) and potassium (192.3 Kg/ha). 

Data collection and analysis
 
After the harvesting biological yield (q/ha), straw yield (q/ha), grain yield (q/h) and harvest index (%) are calculated along with samples of grain and straw were taken for further analysis of NPK uptake in grain and straw using appropriate procedures. Grain and straw samples were taken at maturity and dried at 65^oC until a consistent weight was reached to assess NPK absorption. The dried samples were pulverized and digested to measure the N content using the wet digestion technique (Keeney and Nelson, 1982). The colorimetric method (Olsen et al., 1954) and flame photometry (Brown, 1963) were used to estimate the P and K contents, respectively. The nutrient content in the tissue was multiplied by the dry matter yield of grain and straw to determine the absorption of N, P and K.

 
Statistical analysis
 
Data was analysed in OPSTAT (Operational Statistics). The least significant difference (LSD) at p<0.05 was used to compare the treatment means. Data were combined for two years as the trend of findings in the two years did not differ significantly.

Yield attributes
 
Grain yield
 
According to Table 1, it was observed that Rice straw and nitrogen management had a significant effect on grain yield. The highest grain yield was recorded under straw decomposition with Pusa decomposer (S₂ at 49.75 q/ha) which was 31.12% higher than the control (S₀, 37.94 q/ha). Sowing with a Super seeder (S₁) also improved grain yield (44.96 q/ha, 18.50% higher than S₀). The increased grain yield in S₂ could be attributed to better nutrient recycling, improved soil health and enhanced microbial activity (Prem et  al., 2024). Whereas, in N application increasing nitrogen application significantly boosted grain yield. The highest yield (51.26 q/ha) was observed at 125% RDN (N₃), which was significantly 53.93% higher than the control (N₀, 33.30 q/ha). These findings are similar to Kumar and Pareek (2022) and Yan et al., (2023).



Straw yield
 
It was revealed by the data presented in Table 1 that straw yield followed a similar trend as grain yield, with the highest yield recorded in the Pusa decomposer (S₂) treatment at 69.87 q/ha, which was 27.29% higher than the control (S₀, 54.89 q/ha). Sowing with a super seeder (S₁) also increased straw yield (63.09 q/ha, 14.94% higher than S₀). The improvement in straw yield can be attributed to better decomposition, enhanced soil organic matter and improved crop growth conditions (Ouyang et. al., 2021). Among nitrogen levels, the highest straw yield (67.71 q/ha) was obtained with 125% RDN (N₃), which was 25.22% higher than N₀ (54.07 q/ha). The difference between 100% RDN (N₂) and 125% RDN (N₃) was minimal (only 0.47%), suggesting that 100% RDN was sufficient for optimizing straw yield. These findings were supported by Maarastawi et al., (2018), Chen et al., (2018), Yang et al., (2024) and Guan et al., (2020).

Biological yield
 
Biological yield, which is the sum of grain and straw yield, which was also significantly influenced by treatments. The highest biological yield was observed in S₂ (119.62 q/ha), which was 28.85% higher than the control (S₀, 92.83q/ha). The S₁ treatment also showed an improvement (108.06 q/ha, 16.40% higher than S₀). The increase in biological yield under S₂ might be due to the enhanced decomposition of rice straw, leading to better nutrient availability and plant growth (Ling et al., 2024). Regarding nitrogen levels, biological yield increased with increasing nitrogen application, with N₃ (118.97 q/ha) being 36.16% higher than N₀ (87.37 q/ha). Similar findings were supported by Yang et al., (2024) and Guan et al., (2020).
 
Harvest index
 
The harvest index (HI) was statistically non-significant across treatments, though slight improvements were observed. The highest HI was recorded in S₂ (41.39%), which was slightly higher than S₁ (41.37) and S₀ (40.65%). Similarly, N₃ showed highest (43.05%) HI which was slightly highest compared to N₀ (38.08%). The slight improvement in HI under S₂ and N₃ indicates better partitioning of biomass toward grain yield. However, since the differences were non-significant, it suggests that while nutrient management influences overall yield, the proportional distribution of biomass between grain and straw remains relatively stable.
 
Nutrient uptake in grain and straw
 
According to Fig 1, 2 and 3, it was revealed that rice straw management and nitrogen application significantly influenced nutrient uptake. The highest N uptake was recorded in Pusa decomposer (S₂), with 103.6 kg/ha in grains and 36.09 kg/ha in straw, followed by super seeder (S₁), while the lowest was in control (S₀). Similarly, 125% RDN (N₃) had the highest nitrogen uptake (103.64 kg/ha in grains, 34.07 kg/ha in straw), followed closely by 100% RDN (N₂). For phosphorus uptake, S₂ recorded the highest values (19.89 kg/ha in grains, 9.77 kg/ha in straw), while N₃ had the maximum uptake among nitrogen levels (19.71 kg/ha in grains, 9.28 kg/ha in straw). Likewise, potassium uptake was highest in S₂ (24.40 kg/ha in grains, 125.37 kg/ha in straw), with N₃ (24.74 kg/ha in grains, 117.71 kg/ha in straw), showing the highest uptake among nitrogen levels. This result was supported by Akwakwa et al., (2023); Cui et al., (2022) and Ramteke et al., (2022). 

It was concluded by the above results that managing rice straw leads to increased absorption of essential nutrients such as nitrogen, phosphorus and potassium in both wheat grain and straw, with elevated nitrogen levels further enhancing nutrient content in both grain and straw. Moreover, the incorporation of rice straw and higher nitrogen applications resulted in a more fertile and productive soil environment. Enhanced yield and yield attributing parameters including grain yield, straw yield, biological yield and harvest index. In summary, the study highlights the importance of integrating organic amendments like rice straw with effective nitrogen management to promote sustainable agriculture, enhance nutrient cycling and preserve long-term soil fertility. These practices are crucial for increasing crop yields and  and improving overall farm productivity while minimizing the environmental footprint of intensive farming systems.

All the authors acknowledge and thank Division of Agronomy, Lovely Professional  University,  Phagwara for their guidance and support.
 
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, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
 
Informed consent
 
All experimental procedures and handling techniques were approved Lovely Professional University, Punjab.

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.