BIOCHAR AND FERTILIZER - N EFFECT ON PRODUCTIVITY OF RICE-BLACKGRAM SEQUENCE
Loading...
Date
2023-11-15
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Acharya N G Ranga Agricultural University
Abstract
A field experiment entitled “Biochar and fertilizer - N effect on productivity of rice-blackgram sequence” was conducted for two consecutive years (2020-21 and 2021-22) on sandy clay loam soils of the Agricultural College Farm, Bapatla. The experimental site was uniform in topography and homogeneously fertile. The soil pH was slightly alkaline in reaction, low in organic carbon, low in available nitrogen, medium in available phosphorus and high in potassium.
The experiment was laid out in split plot design replicated thrice. The kharif experiment on rice consisted of four rice husk biochar doses viz.,control (M1), 2.5 t ha-1 (M2), 5.0 t ha-1 (M3) and 7.5 t ha-1 (M4); as main plot treatments. Five nitrogen levels to rice viz., control (S1), 40 kg N ha-1 (S2), 80 kg N ha-1 (S3), 120 kg N ha-1 (S4) and 160 kg N ha-1 (S5) as sub plot treatments. The rabi experiment was continued on succeeding blackgram in the un distributed layout (spilt plot design) to find out the residual effect of the treatments imposed to rice.
The application of biochar @ 7.5 t ha-1 (M4) recorded significantly higher growth parameters of rice viz., plant height, number of tillers-1, drymatter production, LAI, SPAD values and CGR than other treatments but were comparable with biochar @ 5.0 t ha-1 (M3) treatment with similar trend in both the years of study. The lowest growth parameters were recorded in control treatment (M1). The influence of biochar levels exhibited non significant associated with respect to RGR. Among nitrogen levels, the application of 160 kg N ha-1 (S5) registered significantly the highest plant height, number of
xxiv
tillers-1, drymatter production and leaf area index at harvest than others except 120 kg N ha-1. The highest values of SPAD, CGR, RGR and NAR also recorded highest under S5 treatment than others and were comparable with 120 kg N ha-1 (S4) treatment regarding all growth parameters. The lowest growth parameters were registered in control (S1) treatment.
Yield attributes viz; number of panicles m-2, Panicle length, total number of grains panicle-1 and grain yield panicle-1 were higher under biochar @ 7.5 t ha-1 (M4) than other treatments except the application of biochar @ 5.0 t ha-1. Test weight of rice did not alter to an infeasible extent during both the years of study. Application of 160 kg N ha-1 (S5) registered higher number of panicles m-2, total number of grains panicle-1, panicle length and grain yield panicle-1, which was however comparable with S4 treatment and the control treatment was reported lower yield parameters. Various nutrient management practices did not influence the test weight of rice during both the years of study.
The higher grain and straw yields were observed with biochar @ 7.5 t ha-1 (M4) and the lowest yields were registered under control treatment (M1) during both the years of study. Significantly the highest grain and straw yields of rice recorded with application of 160 kg N ha-1 (S5) superior over other treatmentsand it was found comparable with S4 treatment and the lowest yields were exhibited in control treatment (S1) treatment during both the years of study.
Quality parameters like milling, volume expansion ratio, crude protein content, L/B ratio and head rice recovery per cent were not significantly influenced by rice husk biochar during both the years of study and in pooled data. The highest values of these quality parameters were recorded at highest level of nitrogen (160 kg N ha-1), which was comparable with that of 120, 80 and 40 kg N ha-1 but it was significantly superior to that of control treatment.
The content and uptake of nitrogen at different growth stages of rice were significantly influenced by biochar as well as nitrogen levels and the highest values were recorded with biochar @ 7.5 t ha-1 (M4) and 160 kg N ha-1 (S5). Grain and straw nutrient content of phosphorus and potassium were uninfluenced by biochar and nitrogen levels. The application of rice husk biochar @ 7.5 t ha-1 registered significantly the highest phosphorus and potassium uptake by grain and straw than other treatments and it was on par with the application of rice husk biochar @ 5.0 t ha-1 treatment uptake during both the years of study and in pooled data. Application of 160 kg N ha-1 registered higher phosphorus and potassium uptake by grain and straw and the control treatment was registerd the lowest upatake values.
Analysis of economic return indicated that biochar @ 7.5 t ha-1 (M4) was superior to other treatments, however which was however comparable with M3 treatment. Incase of nitrogen levels, the application of 160 kg N ha-1 treatment (S5) registered higher economic return but was comparable with S4 treatment. The lowest economic return was realized in control treatment during both the years of study.
xxv
Plant height, no. of branches plant-1 and drymatter accumulation of succeeding blackgram were significantly affected by residual outcome of diversified biochar and nitrogen levels imposed in rice during both the years of study The higher growth parameters of blackgram obtained with the biochar @ 7.5 t ha-1 and was on a par with the biochar @ 5.0 t ha-1 treatment. Among residual nitrogen levels, significantly the taller plants, more number of branches plant-1 and higher drymatter accumulation of rabi blackgram recorded with 160 kg N ha-1 treatment applied to kharif rice superiot over other treatments and it was comparable with 120 kg N ha-1 treatment during both the years of study and in pooled data.
Yield attributes, yield, quality, nutrient uptake and economic return of rabi blackgram were significantly influenced by biochar and nitrogen levels imposed to kharif rice. The higher yield attributes, yield, quality, upatake and economic returns of blackgram registered with the biochar @ 7.5 t ha-1 applied to kharif rice and it was on a par with biochar @ 5.0 t ha-1 treatment. With respect to nitrogen levels, the higher values of these parameters of blackgram were obtained with 160 kg N ha-1 treatment applied to kharif rice and it was comparable with 120 kg N ha-1 treatment during both the years of study and in pooled data.
Physical properties of soil viz; pH and bulk density after harvest of rice and blackgram was not influenced significantly by biochar and nitrogen treatments imposed to kharif rice crop. After harvest of rice and blcakgram, the higher organic carbon content, water holding capacity and cation exchange capacity were registered with the application of biochar @ 7.5 t ha-1 over biochar @ 2.5 t ha-1 and control treatments. The control treatment recoded the lower values during 2020-21, 2021-22 and in pooled data. Application of 160 kg N ha-1 was registered higher organic carbon content and cation exchange capacity as compared to other treatments except 120 kg N ha-1 during the first and second years of experimentation and in pooled data as well. In two successive years and in pooled analysis, significantly the highest residual available nitrogen, phosphorus and potassium were recorded with the biochar @ 7.5 t ha-1 and the application of 160 kg N ha-1 treatment.
A significant increase in rice equivalent yield observed in biochar @ 7.5 t ha-1 imposed to preceding rice crop over other treatments and was comparable with biochar @ 5.0 t ha-1. With respect to nitrogen treatments, application of 160 kg N ha-1 treatment to kharif rice manifested significant superiority over rest of the treatments but was comparable with 120 kg N ha-1 treatment during both the years of study.