Abstract
Nitrogen and carbon sources are important for the growth and yield of chili. A combination of nitrogen and charcoal shows the potential to increase the availability of nutrients and stimulate plant performance. Therefore, an experiment was conducted to investigate the influence of different levels of nitrogen and charcoal on the growth and yield of chili. A pot experiment was carried out at Lamjung Campus, Lamjung, Nepal from 2019 to 2020. The experiment was carried out using two-factor Completely Randomized Design (CRD) with five replications. Twelve treatments consisted of three levels of nitrogen (0, 50 and 100 kg N ha−1) and four levels of charcoal (0, 2.5, 5 and 7.5% by soil weight) were used in the experiment. Nitrogen and charcoal showed a significant effect on different growth and yield parameters. Nitrogen application at the rate of 100 kg N ha−1 showed significantly the maximum number of primary branches (8.25), plant height (52.62 cm), leaf area (54.33 cm2), number of fruits per plant (42.95), fruit length (6.97 cm), yield per pot (97.14 g) and root length (29.87 cm). The application of 2.5% charcoal by soil weight showed a significant effect on plant height (53.60 cm), fruit length (7.12 cm) and yield per pot (77.55 g), while the application of 5% charcoal by soil weight produced the maximum number of fruits per plant (31.93). The combined level of nitrogen @ 100 kg N ha−1 and charcoal @ 2.5% by soil weight produced the yield per plot (127.1 g). This study suggests that chili production can be maximized by applying such a combined level of nitrogen and charcoal in the Lamjung.
Keywords: Chili, Charcoal, Nitrogen, Growth, Yield, Pot experiment
1. Introduction
Chili is one of the important fruit vegetable or condiment (spice) belongs to the family Solanaceae. Nepal has a total area of 9687 ha allocated to chili cultivation, with a production of 100,344 metric tons and a productivity of 10.35 MT/ha [1]. It is an integral component of every Nepalese kitchen. Because of the pungency, pleasant flavor as well as of medicinal importance, fruit of pepper are in high demand thus it has attained the status of a high-value crop. Hot peppers are also used in industries for the manufacture of various products like chips, chilly powered, sauces etc. In addition to this, chili have antioxidant, antimutagenic, and hypocholesterolemic properties [2]. Globally, chili act as a source of revenue for farmers resulting in poverty alleviation and improvement of women's social status [3]. Similarly, vegetable farming including chili has been widely adopted by the people across all parts of Nepal including Lamjung as a part of their employment as well a way of life for rural farmers.
Nitrogen occupies conspicuous place in plant metabolic system and is the most important nutrient for plants to perform well. In the soil, it exists in two forms: organic and inorganic nitrogen. Most of the organic nitrogen is transformed to inorganic ammonium and nitrate, which plants use [4]. Nitrogen is also a key component of proteins, nucleic acids, and chlorophyll. The use of nitrogen fertilizer is crucial for improving the fruit production in chili [5]. According to numerous studies [6,7], the buildup of too much nitrate can lower agricultural yield because it inhibits photosynthesis and enzyme activity. Uptake and utilization of potassium, and phosphorous, which is also important nutrients for the growth and yield of chilies, can be enhanced by nitrogen and regulates the overall growth and development of plant [8,9].
When a chemical fertilizer is put into the soil, it is quickly depleted, either through leaching or degradation into a different form. Similarly, manure or compost can be drained from the soil, putting farmers under further financial strain. To provide food security for the growing population, agricultural production must be intensified in particular. It is only possible to sustain high quantities of soil organic matter by using carbonized materials derived from the incomplete combustion of organic compounds, such as charcoal [10], which is a carbon-rich solid and porous substance with excellent water and air retention properties that is made by heating biomass in an oxygen-depleted environment. The use of charcoal as a soil additive is analogous to the “slash-and-burn” method of fertilization. Humans began producing and using charcoal around 2500 years ago, according to archeological data. The first proof was discovered in South America's Amazon Basin [11], where Terra Preta conferred three times higher soil organic matter and nutrient levels [12]. The largest percentage of charcoal was employed as a soil supplement in agricultural land in Japan [13]. More importantly, using charcoal as a soil supplement has been shown to improve bioavailable water, soil organic matter, and increase the population of beneficial microorganisms due to the physical refuge given by the charcoal [14]. The potential of charcoal in soil act as suitable soil amendments for plant growth due to its ability to boost soil fertility and soil quality by raising soil pH, increasing moisture-holding capacity, improving cation exchange capacity (CEC), and retaining nutrients in the soil [15, 16]). Many studies have found that applying charcoal to soil improves soluble nitrogen adsorption [17,18,19,20,21].
Furthermore, growers' haphazard nitrogen administration causes deficiency or toxicity in crops, resulting in a considerable drop in crop yield. Moreover, most farmers are unaware of the optimal utilization of nitrogen fertilizer and charcoal effect. In these circumstances, fertilizer in combination with charcoal might be more beneficial. [22] discovered a similar correlation between enhanced peanut yield and increased pH, accessible nitrogen/phosphorus, and CEC. Many plants and soil scientists advise using charcoal to increase soil quality and plant growth [23]. Given the importance of the crop in the area, soil nutrient depletion, and a lack of adequate recommendations, a study is required to make recommendations for economically practical fertilizer application. With the help of this research, farmers will be able to learn about the importance of an adequate amount of nitrogen on the growth and yield parameters of chili, as well as the substantial importance of charcoal on the growth production of chili. Hence, the objective of the experiment was to investigate the effect of different levels of charcoal and nitrogen on and yield traits in chili.
2. Materials and methods
2.1. Experimental location
A pot experiment was conducted at the Horticulture Farm of the Institute of Agriculture and Animal Science (IAAS), Lamjung, Nepal from August 2019 to January 2020. The farm is located at 28.13°N latitude, 84.42°E longitude and 630 m altitude. The pot experiments was conducted outdoors. The meteorological data during the experiment is given in Fig. 1. The initial soil properties were analyzed at National Soil Science Research Centre, Khumaltar, Lalitpur, Nepal for soil physicochemical analysis. The physical and chemical properties of the experimental site is given in Table 1 [24].
Fig. 1.
Meteorological data of the experimental location in 2019–2020.
Table 1.
Soil physical and chemical properties of experimental site.
| Soil Component | Values | Remarks |
|---|---|---|
| pH | 5.93 | Acidic |
| N% | 0.18 | Medium |
| P (kg ha−1) | 35.5 | Medium |
| K (kg ha−1) | 1098.8 | High |
| OM | 3.63 | Medium |
| Sand | 56 | |
| Slit | 29.7 | |
| Clay | 14.3 | |
| Soil texture | Sandy Loam |
(Source: [24]
2.2. Description of experimental materials
Variety “NS 1701” of chili was grown in this experiment. This variety can be cultivated in the Lamjung district of Nepal. The seeds were obtained from Dawadi Agrovet, Narayangarh, Chitwan, Nepal. The source of the nitrogen fertilizer was urea (46% N). The urea, single super phosphate (SSP), muriate of potash (MOP) and charcoal were obtained from the same Agrovet. The farmyard manure (FYM) used in this experiment was cattle FYM. It was matured after 5 months of decomposition.
2.3. Experiment design, treatment details and cultural practices
The experiment was carried out using a two-factor completely randomized design with 12 treatments and five replications. The two factors include nitrogen and charcoal where, nitrogen was one factor with three different levels 0, 50 and 100 kg N ha−1 (=0, 2 and 4 g per pot) and charcoal was another factor at the rate of 0, 125, 250 and 375 g charcoal per pot (=0, 2.5, 5 and 7% by soil weight) were applied in the experiment (Table 1). Twelve treatments were replicated five times, thus there were altogether 60 pots in an experiment where a single pot was considered an experimental unit. Pot has a capacity of 5 kg soil with a top diameter of 22.5 cm, base diameter of 16.5 cm, and height of 18 cm was filled with 5 kg of forest soil and mixed uniformly with FYM viz. 10 t ha−1 (180 g per pot). Nitrogen in the form of urea was applied as per the treatments in three different doses viz. 0 kg N ha−1, 50 kg N ha−1, and 100 kg N ha−1 whereas phosphorous and potassium in the form of SSP and MOP were applied as per the recommended dose (100:100 kg P2O5:K2O ha−1) [1] (Table 2 ). Variety “NS 1701” of chili was planted on first week of August 2019 at the depth of 4–5 cm in a plot of 1 m × 1 m. After the appearance of 3–4 leaves, healthy, robust, and uniform seedlings were transplanted on September 6, 2019 during evening time, and light irrigation was applied immediately. Drip irrigation was applied to pots in this experiment. Pots were watered to field capacity. The fertilizer requirement per pot was calculated according to the required spacing of chili (60 cm × 30 cm). A full dose of P (11 g plant−1) and K (3 g plant−1) was applied while half of the urea viz. 2 g per plant (0, 1, and 2 g plant−1) at the basal dose and remaining urea was applied at two split doses viz. (0, 0.5, and 1 g plant−1) and (0, 0.5 and 1 g plant−1) at 25 days and 55 days respectively as per treatment. The charcoal consists of lignin, resin, pectin, and volatile materials [25,26]. It was collected in a pit, and a fire was started in it then another layer of wood was applied to limit oxygen. Water was sprinkled over it when it became a dark reddish color up to which it had been cooled down and grounded into a powder and was applied to the pot as per treatment. Then, to promote a healthy crop's growth in accordance with the need, the conventional agronomical practices—such as irrigation, cross-cultural activities, and insecticide application—were implemented. To protect chili plants from aphids, insecticide ‘Roger’ at the rate of 2 mL L−1 of water was applied and to supply micronutrient, Agroliv at the rate of 2.5 mL L−1 of water was applied. Harvesting was done when the fruit of chili achieved dark green color, where the first harvesting was done at 32 DAT (Days After Transplanting). The light irrigation was given in pots just after seed sowing and continued at 7–10 days interval. Furrow irrigation was provided 20 days after transplanting.
Table 2b.
NPK application at basal and split-dose for pot experiment of chili.
| Fertilizers | Basal dose (g) | Split dose (g) |
|---|---|---|
| Urea | 0, 1 and 2g pot−1 | At 25 days (0,0.5 and 1 g pot−1) At 55 days (0, 0.5 and 1 g pot−1) |
| SSP | 11 g pot−1 | _ |
| MOP | 3 g pot−1 | _ |
SSP: Single Super Phosphate and MOP: Muriate of Potash.
Table 2a.
Details of factors used in treatments in the experiment
| Factor A (Nitrogen levels) | Factor B (Charcoal levels) |
|---|---|
| N1: 0 kg N ha-1 = 0 g pot-1 (Control) | C1: 0% by soil weight = 0 g charcoal pot-1(Control) |
| N2: 50 kg N ha-1 = 2 g pot-1 | C2: 2.5% by soil weight = 125 g charcoal pot-1 |
| N3: 100 kg N ha-1 = 4 g pot-1 | C3: 5% by soil weight = 250 g charcoal pot-1 |
| C4: 7.5% by soil weight = 375 g charcoal pot-1 |
Where soil weight = 5 kg soil of pot.
2.4. Data collection and observations
Data were collected for all traits from ten plants chosen at random from each experimental plot. Data collection and observation were done for the number of primary branches, plant height (cm), leaf area (sq. cm), the number of fruits per plant, fruit length (cm), yield per plant (g), and root length (cm).
2.5. Statistical analysis
Data were recorded and entered into MS-Excel 2016. Outliers are removed and data was processed so that it follows normal distribution. The data were analyzed using R-Studio (version February 1, 5033). Completely randomized design two-way ANOVA was used to analyze data. LSD test were used for any significant differences at the p < 0.05 level between the means.
3. Results
3.1. Effect of nitrogen and charcoal levels on growth traits
The results of the experiment conducted at given soil and climatic parameters of Lamjung Campus, Lamjung, Nepal from 2019 to 2020 was given in Table 3, Table 4, Table 5. The nitrogen levels produced significant (p < 0.001) differences for the number of primary branches (Table 3). The highest number of primary branches (8) was found with the application of 100 kg N ha−1 followed by 50 kg N ha−1 (7). These two results were at par with each other, and the lowest number of primary branches (6) was observed with the application of 0 kg N ha−1. In general, the number of primary branches increased with an increasing level of nitrogen. However, the application of charcoal and the interaction between nitrogen and charcoal did not bring any changes in the number of primary branches (Table 4, Table 5).
Table 3.
Effects of different levels of nitrogen on number of primary branches, plant height, leaf area, number of fruits per plant, fruit length, yield per pot, and root length of chili at Lamjung, Nepal in 2019–2020.
| Nitrogen Levels (kg/ha) |
Number of primary branches | Plant height (cm) | Leaf area (cm2) | Number of fruits per plant | Fruit length (cm) | Yield per pot (g) | Root length (cm) |
|---|---|---|---|---|---|---|---|
| N1 (0 kg N ha−1) | 6.05b | 45.75b | 32.5c | 12.10c | 6.07b | 27.26c | 25.11b |
| N2 (50 kg N ha−1) | 7.75a | 49.93a | 42.87b | 30.65b | 6.85a | 66.67b | 29.35a |
| N3 (100 kg N ha−1) | 8.25a | 52.62a | 54.33a | 42.95a | 6.97a | 97.14a | 29.85a |
| Mean | 7.35 | 49.43 | 43.25 | 28.56 | 6.63 | 63.69 | 28.11 |
| F test | *** | ** | *** | *** | *** | *** | * |
| LSD (0.05) | 1.01 | 3.99 | 5.5 | 6.08 | 0.42 | 10.62 | 3.83 |
*Significant at 0.05 level of significance, ** Significant at 0.01 level of significance, *** Significant at 0.001 level of significance. LSD: Least Significant Difference. Means followed by the same letters in the same column are not significantly different at the 0.05 level of probability.
Table 4.
Effects of different levels of charcoal on number of primary branches, plant height, leaf area, number of fruits per plant, fruit length, yield per pot, and root length of chili cultivated at Lamjung, Nepal in 2019–2020.
| Charcoal levels (%/soil weight) | Number of primary branches | Plant height (cm) | Leaf area (cm2) | Number of fruits per plant | Fruit length (cm) | Yield per pot (g) | Root length (cm) |
|---|---|---|---|---|---|---|---|
| C1 (0% charcoal by soil weight) | 7.7 | 45.42c | 44.41 | 22b | 6.16c | 49.94c | 29.44 |
| C2 (2.5% charcoal by soil weight) | 7 | 53.60a | 45.99 | 31.2a | 7.12a | 77.55a | 29.16 |
| C3 (5% Charcoal by soil weight) | 7.4 | 50.74 ab | 40.26 | 31.93a | 6.68 ab | 59.70bc | 27.34 |
| C4 (7.5% charcoal by soil weight) | 7.2 | 47.98bc | 42.34 | 29.13a | 6.55bc | 67.56 ab | 6.5 |
| Mean | 7.35 | 49.43 | 43.25 | 28.56 | 6.63 | 63.69 | 28.11 |
| F test | NS | ** | NS | * | ** | *** | NS |
| LSD (0.05) | 1.17 | 4.61 | 6.35 | 7.02 | 0.48 | 12.27 | 4.42 |
NS: Not significant, *Significant at 0.05 level of significance, ** Significant at 0.01 level of significance, *** Significant at 0.001 level of significance. LSD: Least Significant Difference. Means followed by the same letters in the same column are not significantly different at the 0.05 level of probability. Soil weight: 5 kg soil of pot.
Table 5.
Interaction effect of different levels of nitrogen and charcoal on number of primary branches, plant height, leaf area, number of fruits per plant, fruit length, yield per pot, and root length of chili at Lamjung, Nepal in 2019–2020.
| Treatments (Nitrogen × Charcoal levels) | Number of primary branches | Plant height (cm) | Leaf area (cm2) | Number of fruits per plant | Fruit length (cm) | Yield per pot (g) | Root length (cm) |
|---|---|---|---|---|---|---|---|
| N1 × C1 | 6.4 | 44.26 | 31.83 | 10.2 | 5.92 | 26.70i | 23.28 |
| N1 × C2 | 5.8 | 51.78 | 37.59 | 14.8 | 6.74 | 36.59h | 26.76 |
| N1 × C3 | 6.8 | 44.98 | 29.21 | 13.2 | 5.84 | 22.83j | 26.44 |
| N1 × C4 | 5.2 | 41.98 | 31.58 | 10.2 | 5.78 | 22.91j | 23.96 |
| N2 × C1 | 7.8 | 47.14 | 40.74 | 26.4 | 6.14 | 63.55f | 31.06 |
| N2 × C2 | 6.6 | 53.76 | 45.97 | 32 | 7.24 | 68.98d | 31.24 |
| N2 × C3 | 8.6 | 51.02 | 44.13 | 29.8 | 7.14 | 64.89e | 29.38 |
| N2 × C4 | 8 | 47.82 | 40.65 | 34.4 | 6.88 | 69.25d | 25.74 |
| N3 × C1 | 9 | 44.86 | 60.67 | 29.4 | 6.44 | 59.58g | 34 |
| N3 × C2 | 8.6 | 55.28 | 54.42 | 46.8 | 7.4 | 127.1a | 29.5 |
| N3 × C3 | 6.8 | 56.22 | 47.43 | 52.8 | 7.06 | 91.36c | 26.2 |
| N3 × C4 | 8.6 | 54.15 | 54.8 | 42.8 | 7 | 110.5b | 29.8 |
| Mean | 7.35 | 49.43 | 43.25 | 28.56 | 6.63 | 63.69 | 28.11 |
| SD | 1.88 | 7.36 | 12.40 | 16.35 | 0.82 | 35.86 | 6.27 |
| F test | NS | NS | NS | NS | NS | ** | NS |
| LSD (0.05) | 2.02 | 39.44 | 11 | 12.16 | 0.84 | 0.49 | 7.67 |
NC: Nitrogen × Charcoal. NS: Not significant, ** Significant at 0.01 level of significance. SD: Standard deviation, LSD: Least Significant Difference. Means followed by the same letters in the same column are not significantly different at the 0.05 level of probability.
The application of nitrogen levels gave significant (p < 0.01) differences for the plant height. The highest plant height (52.62 cm) was found with the application of 100 kg N ha−1, which was statistically at par with 50 kg N ha−1 (49.93 cm), whereas the smallest pant height (45.75 cm) was found with the application of 0 kg N ha−1 (Table 3). Similarly, the application of charcoal produced significant (p < 0.01) differences for plant height. Plant height varied from 53.60 cm to 45.42 cm. The application of 2.5% charcoal by soil weight gave the maximum plant height (53.60 cm), whereas the shortest plant height (45.42 cm) was found with the application of 0% charcoal by soil weight (Table 4). However, plant height remained unchanged for interaction between nitrogen and charcoal levels (Table 5).
Leaf area significantly varied with nitrogen levels. A higher plant spread (54.33 cm2) was obtained with the application of 100 kg N ha−1 followed by 50 kg N ha−1 (42.87 cm2) while the minimum plant spread (32.5 cm2) was found with the application of 0 kg N ha−1 (Table 3). However, charcoal and the combined effect nitrogen and charcoal levels did not bring any significant difference on the plant spread of chili (Table 4, Table 5).
Root length increased with increasing levels of nitrogen and was found the maximum (29.85 cm) with the application of 100 kg N ha−1 and the minimum (25.11 cm) with the application of 0 kg N ha−1 (Table 3). However, the application of different levels of charcoal and its interaction with nitrogen did not bring any significant difference in the root length (Table 4, Table 5).
3.2. Effect of nitrogen and charcoal levels on yield and yield attributing traits
The application of nitrogen levels produced significant (p < 0.001) differences for the number of fruits per plant (Table 3). Significantly the maximum number of fruits per plant (42.95) was found with the application of 100 kg N ha−1, followed by 50 kg N ha−1 and the minimum number of fruits per plant (12.10) was found at control. Additionally, a significant (p < 0.05) result was observed for the number of fruits per plant with the application of different levels of charcoal (Table 4). The application of 5% charcoal gave the maximum number of fruits per plant (31.93) which was statistically at par with the application of 2.5% charcoal and 7.5% charcoal, whereas the least number of fruits per plant was found at control. However, no significant interactive effect was observed for number of fruits per plant (Table 5).
The application of nitrogen levels significantly (p < 0.01) affected the fruit length of chili. The longest fruit length (6.97 cm) was found with the application of 100 kg N ha−1 which was statistically at par with 50 kg N ha−1. The minimum value of fruit length (6.07 cm) was found at control (Table 3). Generally, the fruit length increased with the increment of nitrogen levels. Moreover, a significant difference was observed for fruit length with the application of different levels of charcoal (Table 4). Fruit length varied from 7.12 cm to 6.16 cm. The application of 2.5% charcoal produced the longest fruit length (7.12 cm) which was statistically at par with 5% charcoal and 7.5% charcoal. However, the shortest fruit length (6.16 cm) was found at control which was statistically at par with 7.5% charcoal. An interactive effect of nitrogen and charcoal levels was found non-significant for fruit length (Table 5).
The yield per pot varied significantly (p < 0.001) with different levels of nitrogen (Table 3). The maximum yield per pot (97.14 g) was found with the application of 100 kg N ha−1 followed by 50 kg N ha−1 (66.67 g) while the minimum yield per pot (27.26 g) was found with the application of 0 kg N ha−1. The results revealed that yield per pot increased with an increment in nitrogen levels applied. Similarly, the application of different levels of charcoal produced significant (p < 0.001) differences for yield per pot. Yield per pot varied from 77.55 g to 49.94 g. The application of 2.5% charcoal gave the maximum yield per pot (77.55 g) which was statistically at par with 7.5% charcoal and 5% charcoal. However, the minimum yield per pot (49.94 g) was found with the application of 0% charcoal by soil weight which was statistically at par with 5% charcoal (Table 4). Additionally, a combined effect of nitrogen and charcoal levels showed highly significant (p < 0.01) results for yield per pot (Table 5). The maximum yield per pot (127.1 g) was found with the application of 100 kg N ha−1 and 2.5% charcoal which was significantly different among other treatment. However, the minimum yield per pot (22.83 g) was found with the application of control nitrogen and 5% charcoal.
4. Discussion
4.1. Effects of nitrogen levels on growth and yield of chili
Nitrogen is an important nutrient for plants since it is a component of chlorophyll and a building block for amino acids and protein. It boosts potassium and phosphorus uptake and utilization while also regulating plant growth and development [27]. As a result, it is involved in practically every metabolic process. The nitrogen level of 100 kg ha−1 resulted in the greatest number of primary branches of chili in our study. These findings corroborate those of [28], who discovered that adding nitrogen increased the number of branches significantly because nitrogen stimulates vegetative growth. Furthermore, enhanced cell division and tissue formation improve the plant's vegetative development, resulting in a long-term improvement in yield. Similarly, the height of the chili plants in our study increased as the amount of nitrogen increased. The results appear to be comparable to those of [29]. Because nitrogen aids in vegetative growth, the number of branches increases, and more branches imply more fruits. [30] discovered that the highest nitrogen amount produced the most fruit. It indicated maximum leaf area due to nitrogen's role in cell division and cell expansion, similar to discovery of [31]. The presence of the essential supplement N in the soil helped to sustain better fruit length, and its application in large quantities helped to improve fruit length. According to our research, the longest chili fruit and chili yield per plot was found at the maximum nitrogen content (100 kg ha−1). It could be because nitrogen helps to build high-quality foliage and plays an important role in carbohydrate synthesis via photosynthesis, resulting in better plant yield. Nitrogen is a part of chlorophyll, which functions as a plant's factory for photosynthesis. Nitrogen has a major influence in the production of leaf area, the duration of leaf area, and the net assimilation rate, all of which are directly related to increased yield [32].
4.2. Effect of charcoal levels on growth and yield of chili
Plant height, number of fruits per plant, fruit length, yield per pot, and average fruit yield were all significant in our study). According to our research, 2.5% charcoal provided the best results for plant height, fruit length, yield per pot, and average fruit yield, though it was comparable to 5% and 7.5% charcoal. [33] inferred that low percentage of charcoal (2% in volume) into composting improved the humidified organic carbon. However, high rate of biochar application reduced the concentrations of nitrate, ammonium, and orthophosphate in the first sampling season of soil water solution in turfgrass system, which lasted an extra year for the nitrate concentration [34].
4.3. Interaction effect of nitrogen and charcoal levels on growth and yield of chili
According to our research, combining charcoal with nitrogen resulted in a considerable increase in yield per pot. The reason for this could be that the use of charcoal in conjunction with fertilizer resulted in a large increase in nutrient uptake [35]. Biochar boosts soil microbial activity improves N availability, and boosts crop output [36], whereas microorganisms play a key part in the nitrogen cycle [37].
[38] found that the chemical groups on the surface of charcoal are responsible for nitrogen adsorption. Negatively charged acid functional groups, such as carboxylic, hydroxyl, lactone, and lactol, are effective at binding to NH4+ via electrostatic attraction. Basic functional groups on biochar, such as chromes, ketones, and pyrones, can also improve NO3-adsorption [39]. The adsorption of nitrogen on biochar, on the other hand, is dependent on the process time and temperature. Biochar-based fertilizers, for example, have been shown to increase the productivity of green pepper, cabbage, and rice by increasing Nitrogen Use Efficiency (NUE) [40,41,42,43]. The discovery of an increase in production owing to the addition of nitrogen to charcoal is similar to the findings of [44]. Furthermore, [45] found that pepper and tomato plants were less susceptible to two contagious diseases (Botrytis cinerea and Leveillula Taurica), and pepper to a foliar mite, when grown (Polyphagotarsonemus latus). Similarly, a charcoal adjusted mixture shared root-associated bacterial isolates such as Pseudomonas, Mesorhizobium, Brevibacillus, Bacillus, and Streptomyces strains that operate as either/or both plant growth promoters and biocontrol agents against a variety of plant diseases [46]. According to Ref. [47]; 1% biochar combined with lower fertilizer doses can successfully boost wheat growth, yield, nutritional content, and absorption. When compared to merely fertilizer application, the synergistic effect of charcoal plus fertilizer treatments enhances yield [48].
5. Conclusion
The application of nitrogen @ 100 kg ha−1 increased the growth and yield of chili, whereas 2.5% charcoal produced significant increments for plant height, fruit length, and yield per. The combination of nitrogen @ 100 kg ha−1 and 2.5% charcoal by soil weight gave the maximum yield of chili and was found non-significant for remaining growth and yield parameters. Therefore, the application of combination of nitrogen @ 100 kg ha−1 +2.5% charcoal by soil weight was found to be the optimum level for the cultivation of chili.
Author contribution statement
Puja Subedi, Prayusha Bhattarai, Babita Lamichhane, Amit Khanal: Conceived and designed the experiments; Performed the experiments; Analyzed and interpreted the data; Wrote the paper.
Jiban Shrestha: Contributed reagents, materials, analysis tools or data; Wrote the paper.
Funding statement
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Data availability statement
Data will be made available on request.
Declaration of interest’s statement
The authors declare no conflict of interest.
Contributor Information
Puja Subedi, Email: subedipuja263@gmail.com.
Prayusha Bhattarai, Email: prayushab499@gmail.com.
Babita Lamichhane, Email: lbabita02@gmail.com.
Amit Khanal, Email: a.khanal@uq.net.au.
Jiban Shrestha, Email: jibshrestha@gmail.com.
References
- 1.MOALD . vol. 77. 2019. pp. 1–237. (Stattistical Information on Nepalese Agriculture). [DOI] [Google Scholar]
- 2.Bhattacharya A., Chattopadhyay A., Mazumdar D., Chakravarty A., Pal S. Antioxidant constituents and enzyme activities in chilli peppers. Int. J. Veg. Sci. 2010;16(3):201–211. [Google Scholar]
- 3.Karungi J., Obua T., Kyamanywa S., Mortensen C.N., Erbaugh M. Seedling protection and field practices for management of insect vectors and viral diseases of hot pepper (Capsicum chinense Jacq.) in Uganda. Int. J. Pest Manag. 2013;59(2):103–110. [Google Scholar]
- 4.Walworth J. Cooperate Extension Publication AZ1591, University 565 of Arizona; Tucson, Arizona, USA: 2013. Nitrogen in Soil and the Environment; p. 3. [Google Scholar]
- 5.Biswas M., Sarkar D.R., Asif M.I., Sikder R.K., Mehraj H., Jamal Uddin A.F.M. Effect of nitrogen levels on morphological and yield response of BARI tomato-9. Journal of Science, Technology and Environment Informatics. 2015;1(2):68–74. [Google Scholar]
- 6.Aydinsakir K., Karaca C., Ozkan C.F., Dinc N., Buyuktas D., Isik M. Excess nitrogen exceeds the European standards in lettuce grown under greenhouse conditions. Agron. J. 2019;111(2):764–769. [Google Scholar]
- 7.Matsumura A., Hirosawa K., Masumoto H., Daimon H. Effects of maize as a catch crop on subsequent garland chrysanthemum and green soybean production in soil with excess nitrogen. Sci. Hortic. 2020;273 [Google Scholar]
- 8.Alhrout H.H. Response of growth and yield components of sweet pepper to tow different kinds of fertilizers under green house conditions in Jordan. J. Agric. Sci. 2017;9(10):265–272. doi: 10.5539/jas.v9n10p265. [DOI] [Google Scholar]
- 9.Chimdessa A., Bekele M., Obsa C. 2019. Growth and Yield Response of Hot Pepper (Capsicum annuum L.) to NPSB Blended Fertilizers and Farm Yard Manure: A Review. [Google Scholar]
- 10.Glaser B., Lehmann J., Zech W. Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal - a review. Biol. Fertil. Soils. 2002;35(4):219–230. doi: 10.1007/s00374-002-0466-4. [DOI] [Google Scholar]
- 11.Glaser B. Prehistorically modified soils of central Amazonia: a model for sustainable agriculture in the twenty-first century. Phil. Trans. Biol. Sci. 2007;362(1478):187–196. doi: 10.1098/rstb.2006.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Glaser B., Haumaier L., Guggenberger G., Zech W. The “Terra Preta” phenomenon: a model for sustainable agriculture in the humid tropics. Naturwissenschaften. 2001;88(1):37–41. doi: 10.1007/s001140000193. [DOI] [PubMed] [Google Scholar]
- 13.Okimori Y., Ogawa M., Takahashi F. Potential of CO2 emission reductions by carbonizing biomass waste from industrial tree plantation in South Sumatra, Indonesia. Mitig. Adapt. Strategies Glob. Change. 2003;8(3):261–280. doi: 10.1023/B:MITI.0000005643.79908.5a. [DOI] [Google Scholar]
- 14.Warnock D.D., Lehmann J., Kuyper T.W., Rillig M.C. Mycorrhizal responses to biochar in soil - concepts and mechanisms. Plant Soil. 2007;300(1–2):9–20. doi: 10.1007/s11104-007-9391-5. Springer. [DOI] [Google Scholar]
- 15.Lehmann J. Bio-energy in the black. Front. Ecol. Environ. 2007;5(7):381–387. doi: 10.1890/1540-9295(2007)5. [381:BITB]2.0.CO;2. [DOI] [Google Scholar]
- 16.Lehmann J., Gaunt J., Rondon M. Bio-char sequestration in terrestrial ecosystems - a review. Mitig. Adapt. Strategies Glob. Change. 2006;11:403–427. doi: 10.1007/s11027-005-9006-5. [DOI] [Google Scholar]
- 17.Bai S.H., Reverchon F., Xu C.Y., Xu Z., Blumfield T.J., Zhao H., Van Zwieten L., Wallace H.M. Wood biochar increases nitrogen retention in field settings mainly through abiotic processes. Soil Biol. Biochem. 2015;90:232–240. doi: 10.1016/j.soilbio.2015.08.007. [DOI] [Google Scholar]
- 18.Blackwell P., Krull E., Butler G., Herbert A., Solaiman Z. Effect of banded biochar on dryland wheat production and fertiliser use in south-western Australia: an agronomic and economic perspective. Aust. J. Soil Res. 2010;48(6–7):531–545. doi: 10.1071/SR10014. [DOI] [Google Scholar]
- 19.Clough T., Condron L., Kammann C., Müller C. A review of biochar and soil nitrogen dynamics. Agronomy. 2013;3(2):75–293. doi: 10.3390/agronomy3020275. [DOI] [Google Scholar]
- 20.Hosseini Bai S., Xu C.Y., Xu Z., Blumfield T.J., Zhao H., Wallace H., Reverchon F., Van Zwieten L. Soil and foliar nutrient and nitrogen isotope composition (δ15N) at 5 years after poultry litter and green waste biochar amendment in a macadamia orchard. Environ. Sci. Pollut. Control Ser. 2015;22(5):3803–3809. doi: 10.1007/s11356-014-3649-2. [DOI] [PubMed] [Google Scholar]
- 21.Xu N., Tan G., Wang H., Gai X. Effect of biochar additions to soil on nitrogen leaching, microbial biomass and bacterial community structure. Eur. J. Soil Biol. 2016;74:1–8. doi: 10.1016/j.ejsobi.2016.02.004. [DOI] [Google Scholar]
- 22.Fischer D., Glaser B. In Management of Organic Waste. IntechOpen; 2012. Synergisms between compost and biochar for sustainable soil amelioration. [DOI] [Google Scholar]
- 23.Steiner C., Teixeira W.G., Lehmann J., Nehls T., De MacÊdo J.L.V., Blum W.E.H., Zech W. Long term effects of manure, charcoal and mineral fertilization on crop production and fertility on a highly weathered Central Amazonian upland soil. Plant Soil. 2007;291(1–2):275–290. doi: 10.1007/s11104-007-9193-9. [DOI] [Google Scholar]
- 24.Thapa P., Shrestha R.K., Kafle K., Shrestha J. Effect of different levels of nitrogen and farmyard manure on the growth and yield of spinach (Spinacia oleracea L.) J. Agric. Sci. 2021;2(XXXII):335–340. 2021. [Google Scholar]
- 25.Dong T., Gao D., Miao C., Yu X., Degan C., Garcia-Pérez M., Rasco B., Sablani S.S., Chen S. Two-step microalgal biodiesel production using acidic catalyst generated from pyrolysis-derived bio-char. Energy Convers. Manag. 2015;105:1389–1396. doi: 10.1016/j.enconman.2015.06.072. [DOI] [Google Scholar]
- 26.Lai W.Y., Lai C.M., Ke G.R., Chung R.S., Chen C.T., Cheng C.H., Pai C.W., Chen S.Y., Chen C.C. The effects of woodchip biochar application on crop yield, carbon sequestration and greenhouse gas emissions from soils planted with rice or leaf beet. J. Taiwan Inst. Chem. Eng. 2013;44(6):1039–1044. doi: 10.1016/j.jtice.2013.06.028. [DOI] [Google Scholar]
- 27.Alhrout H.H. Response of growth and yield components of sweet pepper to tow different kinds of fertilizers under green house conditions in Jordan. J. Agric. Sci. 2017;9(10):265–276. [Google Scholar]
- 28.Ayodele O.J. Nitrogen fertilizer effects on growth, yield and chemical composition of hot pepper (Rodo) Intl. J. Agric. Crop Sci. 2015;8(5):666–673. [Google Scholar]
- 29.Singegol H.Y., Patil H.B., Patil D.R. Jwala as Influenced by nitrogen and phosphorus. The Asian Journal of Horticulture. 2007;2(2):184–187. [Google Scholar]
- 30.Ghoneim I.M. Effect of nitrogen fertilization and its application systems on vegetative growth, fruit yield and quality of sweet pepper. Journal of Agricultural Science and Environment. 2005;4:58–77. [Google Scholar]
- 31.Taylor G., Mc Donald A.J.S., Stadenberg I., Freer-smith P.H. Nitrate supply and the biophysics of leaf growth in Salix viminalis. J. Exp. Bot. 1993;44(1):155–164. doi: 10.1093/jxb/44.1.155. [DOI] [Google Scholar]
- 32.Leghari S.J., Wahocho N.A., Laghari G.M., HafeezLaghari A., MustafaBhabhan G., HussainTalpur K., Bhutto T.A., Wahocho S.A., Lashari A.A. Role of nitrogen for plant growth and development: a review. Adv. Environ. Biol. 2016;10(9):209–219. [Google Scholar]
- 33.Jindo K., Sánchez-Monedero M.A., Matsumoto K., Sonoki T. The efficiency of a low dose of biochar in enhancing the aromaticity of humic-like substance extracted from poultry manure compost. Agronomy. 2019;9(5):248. [Google Scholar]
- 34.Crutchfield E.F. University of California; Riverside: 2016. Biochar's Effect on Plant Growth and Soil Nutrient Loss. [Google Scholar]
- 35.Piash M.I., Hossain M.F., Zakia P. Effect of biochar and fertilizer application on the growth and nutrient accumulation of rice and vegetable in two contrast soils. Acta Scienctific Agriculture. 2019;3(2):74–83. [Google Scholar]
- 36.Kim P., Hensley D., Labbé N. Nutrient release from switchgrass-derived biochar pellets embedded with fertilizers. Geoderma. 2014;232–234:341–351. doi: 10.1016/j.geoderma.2014.05.017. [DOI] [Google Scholar]
- 37.Nelson M.B., Martiny A.C., Martiny J.B.H. Global biogeography of microbial nitrogen-cycling traits in soil. Proc. Natl. Acad. Sci. U. S. A. 2016;113(29):8033–8040. doi: 10.1073/pnas.1601070113. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Gabhane J., Tripathi A., Athar S., William S.P., Vaidya A.N., Wate S.R. Assessment of bioenergy potential of agricultural wastes: a case study cum template. J Biofuels Bioenergy. 2016;2(2):122–131. [Google Scholar]
- 39.Montes-Morán M.A., Suárez D., Menéndez J.A., Fuente E. On the nature of basic sites on carbon surfaces: an overview. Carbon. 2004;42(7):1219–1225. doi: 10.1016/j.carbon.2004.01.023. [DOI] [Google Scholar]
- 40.Chen L., Chen Q., Rao P., Yan L., Shakib A., Shen G. Formulating and optimizing a novel biochar-based fertilizer for simultaneous slow-release of nitrogen and immobilization of cadmium. Sustainability. 2018;10(8):2740. doi: 10.3390/su10082740. [DOI] [Google Scholar]
- 41.Qian L., Chen L., Joseph S., Pan G., Li L., Zheng J., Zhang X., Zheng J., Yu X., Wang J. Biochar compound fertilizer as an option to reach high productivity but low carbon intensity in rice agriculture of China. Carbon Manag. 2014;5(2):145–154. doi: 10.1080/17583004.2014.912866. [DOI] [Google Scholar]
- 42.Wen P., Wu Z., Han Y., Cravotto G., Wang J., Ye B.C. Microwave-assisted synthesis of a novel biochar-based slow-release nitrogen fertilizer with enhanced water-retention capacity. ACS Sustain. Chem. Eng. 2017;5(8):7374–7382. doi: 10.1021/acssuschemeng.7b01721. [DOI] [Google Scholar]
- 43.Yao C., Joseph S., Li L., Pan G., Lin Y., Munroe P., Pace B., Taherymoosavi S., Van zwieten L., Thomas T., Nielsen S., Ye J., Donne S. Developing more effective enhanced biochar fertilisers for improvement of pepper yield and quality. Pedosphere. 2015;25(5):703–712. doi: 10.1016/S1002-0160(15)30051-5. [DOI] [Google Scholar]
- 44.Wisnubroto E.I., Utomo W.H., Soelistyari H.T. Biochar as a carrier for nitrogen plant nutrition: the release of nitrogen from biochar enriched with ammonium sulfate and nitrate acid. Int. J. Appl. Eng. Res. 2017;12(6):1035–1042. [Google Scholar]
- 45.Elad Y., David D.R., Harel Y.M., Borenshtein M., Kalifa H., Ben Silber A., Graber E.R. Induction of systemic resistance in plants by biochar, a soil-applied carbon sequestering agent. Phytopathology. 2010;100(9):913–921. doi: 10.1094/PHYTO-100-9-0913. [DOI] [PubMed] [Google Scholar]
- 46.Graber E.R., Harel Y.M., Kolton M., Cytryn E., Silber A., David D.R., Tsechansky L., Borenshtein M., Elad Y. Biochar impact on development and productivity of pepper and tomato grown in fertigated soilless media. Plant Soil. 2010;337(1):481–496. doi: 10.1007/s11104-010-0544-6. [DOI] [Google Scholar]
- 47.Hamdani S.A.F., Aon M., Ali L., Aslam Z., Khalid M., Naveed M. Application of dalbergia sissoo biochar enhanced wheat growth, yield and nutrient recovery under reduced fertilizer doses in calcareous soil. Pakistan J. Agric. Sci. 2017;54(1):107–115. doi: 10.21162/PAKJAS/17.5102. [DOI] [Google Scholar]
- 48.Carter S., Shackley S., Sohi S., Suy T., Haefele S. The impact of biochar application on soil properties and plant growth of pot grown lettuce (Lactuca sativa) and cabbage (Brassica chinensis) Agronomy. 2013;3(2):404–418. doi: 10.3390/agronomy3020404. [DOI] [Google Scholar]
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Data Availability Statement
Data will be made available on request.