Integrated Plant Nutrient System Research Articles

A Study on the Impacts of Fertilizer Crisis on Paddy Cultivation in Five Selected Divisional Secretariat Divisions of Trincomalee District During Maha 2021/22

Rice is one of the most important cereal crops in the world. With population growth, farmers have to increase paddy production to meet existing as well as future demand. Fertilizer is the major input in rice production. Growth and yield traits of rice are affected by improper and imbalanced application of plant nutrients. Hence, suitable practices of adequate rate and timing of fertilizer application are needed to increase the rice yield. In May 2021, Imports & Exports (Control) Regulation No 07 of 2021 was issued, banning the importation of chemical fertilizers, pesticides, & herbicides in Sri Lanka. Low fertility of paddy soil created the need for adequate and constant supply of chemical fertilizers in paddy cultivation, which is a major threat to production and endangers the national food security and economy of Sri Lanka, especially in the major cropping season of Maha 2021/22. Therefore, a questionnaire survey was conducted to investigate the impact of the fertilizer crisis in major paddy-cultivating Divisional Secretariat divisions of the Trincomalee district. The random sampling method was used to select respondents for the survey, and the collected data were statistically analyzed by SPSS version 26.0 software. The results revealed that the majority of the farmers experienced a 50% yield reduction compared to the last cropping season of Maha 2020/21 in the entire five DS divisions. The seedling stage was highly affected during the fertilizer crisis in paddy cultivation in all five DS divisions. Further, the cost of production in paddy cultivation increased by more than 50% during the fertilizer crisis compared to the cost involved in Maha 2020/21. The potential for organic manure production is very poor, while the majority of farmers are interested in adopting the sustainable farming system of the Integrated Plant Nutrient System through the judicious application of chemical and organic fertilizers received on a subsidy basis, according to the present government’s fertilizer policy, which emphasizes 70% of inorganic fertilizers and 30% of organic manure application to improve sustainability in paddy cultivation in the country.

Impact of Long Term Integrated Plant Nutrient System (IPNS) in Rice –Wheat Cropping System on Population Dynamics and Dominance of Weed Species in Wheat

Weeds are the serious constraints in field crops. In 2014-15 and 2015-16 long term experiment was conducted which was earlier established from the year 1994 on IPNS in rice-wheat cropping system using randomized block design with four replications at Badiarkhar farm of the university. Twelve treatments viz., control (no fertilizer/manure), 50, 75 and 100% NPK each to rice and wheat through fertilizers, 50% NPK to rice and 100% NPK to wheat through fertilizers, 50% substitution of Nitrogen through FYM, wheat straw and green manure in rice and 100% NPK through fertilizers in wheat; 25% substitution of Nitrogen through FYM, wheat straw and green manure in rice and 75% NPK through fertilizers in wheat; and farmers’ practice (40% NPK through fertilizers to each crop plus 5 t FYM/ha on dry weight basis to rice) were evaluated for a period of two years (2014-15and 2015-16). Phalaris minor was the most dominant weed during both years followed by Alopecurus sp., Vicia sativa, Polygonum hydropiper, Lathyrus aphaca and Polygonum alatum. Artemisia sp. and other weeds had a little infestation during rabi 2014-15. While Cynodon dactylon, Anagallis arvensis, Centella asiatica and other weeds had shown their invasion during rabi 2015-16.

Impact of Long-Term Nutrient Management on Carbon Dynamics under Cluster Bean-Wheat Cropping System in Western Rajasthan, India

A field experiment was started in 2008 under All India Co-ordinated Research Project- Soil Test Crop Response in western Rajasthan to study the long-term effects of nutrient management strategy using Soil Test Crop Response (STCR) approach on cluster bean– wheat cropping system. The present investigation indicated effects of organic compost and inorganic fertilizer as per soil test crop response approach basis on soil carbon dynamics. The treatments consisted of general recommended dose, target yield 15 q ha-1, target yield 15 q ha-1 with Integrated Plant Nutrient System (IPNS), target yield 20 q ha-1 and target yield 20 q ha-1 without Integrated Plant Nutrient System. The soil organic pools were studied after 9 years and it was found that the total C and its different pools of soil increased significantly under target yield 20 q ha-1 with IPNS. Active and passive pools (AP and PP) of carbon of soil increased significantly under target yield 20 q ha-1 with IPNS as compared to the target yield 15 and 20 q ha-1 treatments without IPNS and at par with target yield 15 q ha-1 with IPNS. Carbon management index (CMI) and carbon stock (CS) increased significantly under target yield 20 q ha-1 with IPNS. It can be concluded that combined application of organic and inorganic nutrient in long term basis significantly enhance carbon sequestration rate, consequently soil quality.

Response of Hybrid Castor Under Different Fertility Gradient: Correlation Between Castor Yield and Normalized Difference Vegetation Index (NDVI) Under Inductive Cum Targeted Yield Model on an Alfisol

ABSTRACT Precision application of nutrient based on soil test value is important for improving nutrient use efficiency and yield of hybrid castor. Field trial was conducted during 2021 at Tapioca and Castor Research Station, Yethapur, Salem District, Tamil Nadu, India (11035’ N, 780 29’ E). Fertilizer prescription equations (FPEs) were developed for hybrid castor by adopting inductive cum targeted yield model approach under irrigated condition on Alfisol. Initially, soil fertility gradients were established with respect to soil available N, P and K nutrients, and 24 treatments were imposed in three fertility strips under factorial randomized design. Principle component analysis revealed that all the variables accounted for developing the FPEs of hybrid castor are present at the positive quadrant which mean that all the variables are highly important toward the castor seed yield production. From the field experimental data, the basic parameters [nutrient requirement (NR) and nutrients contributions from farmyard manure (Co), fertilizer (Cf), and soil (Cs)] were computed. The nutrient required for producing one quintal of hybrid castor seed yield was evaluated as 3.20 kg of nitrogen, 1.23 kg of phosphorus pentoxide (P2O5), and 3.28 kg of potassium oxide (K2O). The study revealed that soil nutrient contribution was high in case of available phosphorus (41.87%), available nitrogen (21.56%), and available potassium (19.12%), respectively, toward P, N, and K nutrient uptake by hybrid castor. The nutrient contribution from farmyard manure (Co) toward the total uptake was 21.40% of N, 10.35% of P2O5, and 26.06% of K2O, respectively. FPEs for hybrid castor and a ready reckoner of fertilizer dosages were developed using basic data for operational range of soil test values for intended yield target under inorganic fertilization alone and Integrated plant Nutrient System (IPNS) (NPK and FYM).

Combining Vermicompost with Inorganic Fertilizers Improved Rice Yield and Affected Potassium Pools under Rice-Based Cropping Systems in Inceptisols

Integrated use of inorganic fertilizer and organic manure restores soil quality and increases crop productivity. Potassium (K) pools are also affected in soil due to the rate and sources of nutrients applied. However, the integration of vermicompost and mineral fertilizers effects strongly depends on soil type, and still, no precise information is available for Inceptisols in Eastern India. Keeping this fact in view, a field experiment was conducted at the research farm of Bihar Agriculture University, Sabour, Bihar to understand the effect of soil test crop response (STCR) based balanced fertilization with or without organic manure on soil K pools and rice performance under rice-wheat and rice-maize cropping systems. This experiment included nine treatments viz., general fertilizer recommendation, farmers’ fertilizer practice, STCR with and without Integrated Plant Nutrient System (IPNS)/vermicompost for low (3 t ha−1), medium (4 t ha−1), and high target yield (5 t ha−1) and absolute control (without fertilizer application) which were replicated thrice in a randomized block design (RBD). The highest rice yield was obtained under STCR with IPNS for high target yield (2% more) than the corresponding treatment without IPNS followed by STCR with IPNS for medium target yield however treatments were statistically at par with one another. Benefit cost ratio was significantly highest under STCR with IPNS for medium target yield overall the treatments for both cropping systems. Different forms of K (water-soluble K, exchangeable K, non-exchangeable K, and mineral K) declined under farmers’ practice and absolute control whereas these forms were greater under STCR with IPNS-based treatments than the STCR without IPNS-based treatments in the corresponding target yields. The correlation study suggested that exchangeable K was the most important form, positively and highly significantly related to soil available K (R 2 = 98). Overall, this study recommended that the integrated use of vermicompost and mineral fertilizers (STCR with IPNS) for medium target yield (4 t ha−1) was more responsive toward rice yield as well as K availability for soil sustainability from Inceptisols in eastern India.

Integrated Plant Nutrient Systems Improve Rice Yields without Affecting Greenhouse Gas Emissions from Lowland Rice Cultivation

Efficient management of fertilizers and irrigation could mitigate greenhouse gas (GHG) emissions and increase crop yields. Field experiments were conducted to determine the effects of an integrated plant nutrient system (IPNS) and water regime—alternate wetting and drying (AWD) and continuous flooding (CF)—on GHG emissions and rice yield. Fertilizer treatments included control (no N), prilled urea (PU), urea deep placement (UDP), and IPNS (50% N from poultry litter and 50% N from PU). Gas sampling and analysis were performed using a closed-chamber technique and gas chromatography. IPNS produced significantly (p < 0.05) higher seasonal total methane (CH4) emissions (9–15%) compared to the UDP treatment, but the emissions with IPNS were similar to those of PU. IPNS had an interaction effect with the water regime on nitrogen oxide (N2O) emissions. IPNS produced more emissions than PU under AWD, but their emissions were similar under CF irrigation. IPNS produced a significantly higher total global warming potential (GWP) than UDP but a GWP similar to the PU treatment in both Aus (pre-monsoon) and Aman (wet) seasons. AWD irrigation reduced the total GWP by 8% over CF without yield reductions. IPNS significantly increased rice yields compared to broadcast PU but yields were similar to those of UDP. These findings suggest that both IPNS and UDP could be effective in increasing crop yields without increasing GHG emissions.

Effect of Soil Test Crop Response Approach on Yield, Nutrient Content and Uptake by Wheat (Triticum aestivum L.)

A field experiment was carried out during Rabi season of 2018-19 under AICRP project on Soil Test Crop Response at Agricultural Research Station, Swami Keshwanand Rajasthan Agricultural University, Bikaner to find out the effect of soil test crop response approach on yield, nutrient content and uptake of wheat. The experiment was laid out in randomized block design with five treatment combinations viz. general recommendation dose, soil test crop response recommendation for target yield 30 q ha-1, soil test crop response recommendation for target yield 30 q ha-1 with integrated plant nutrient system, soil test crop response recommendation for target yield 40 q ha-1 and soil test crop response recommendation for target yield 40 q ha-1 with integrated plant nutrient system with four replications. Research finding of long term field experiment revealed that application of soil test crop response recommendation for target yield 40 q ha-1 with integrated plant nutrient system gave maximum number of effective tillers m-1 row length, spike length, number of grains spike-1, weight of grains spike-1, test weight, grain yield (4026 kg ha-1) and straw yield (5629 kg ha-1) of wheat which was found statistically at par with soil test crop response recommendation for target yield 30 q ha-1 with integrated plant nutrient system. Application of soil test crop response recommendation for target yield 40 q ha-1 with integrated plant nutrient system also improved the N, P and K content and their uptake by grain and straw of wheat. These study results proved that soil test crop response recommendation with integrated plant nutrient system gave better results of all parameters in the comparison of general recommendation dose and soil test crop response without integrated plant nutrient system.

Mitigating greenhouse gas emissions from irrigated rice cultivation through improved fertilizer and water management

Greenhouse gas (GHG) emissions from agriculture sector play an important role for global warming and climate change. Thus, it is necessary to find out GHG emissions mitigation strategies from rice cultivation. The efficient management of nitrogen fertilizer using urea deep placement (UDP) and the use of the water-saving alternate wetting and drying (AWD) irrigation could mitigate greenhouse gas (GHG) emissions and reduce environmental pollution. However, there is a dearth of studies on the impacts of UDP and the integrated plant nutrient system (IPNS) which combines poultry manure and prilled urea (PU) with different irrigation regimes on GHG emissions, nitrogen use efficiency (NUE) and rice yields. We conducted field experiments during the dry seasons of 2018, 2019, and 2020 to compare the effects of four fertilizer treatments including control (no N), PU, UDP, and IPNS in combination with two irrigation systems— (AWD and continuous flooding, CF) on GHG emissions, NUE and rice yield. Fertilizer treatments had significant (p < 0.05) interaction effects with irrigation regimes on methane (CH4) and nitrous oxide (N2O) emissions. PU reduced CH4 and N2O emissions by 6% and 20% compared to IPNS treatment, respectively under AWD irrigation, but produced similar emissions under CF irrigation. Similarly, UDP reduced cumulative CH4 emissions by 9% and 15% under AWD irrigation, and 9% and 11% under CF condition compared to PU and IPNS treatments, respectively. Across the year and fertilizer treatments, AWD irrigation significantly (p < 0.05) reduced cumulative CH4 emissions and GHG intensity by 28%, and 26%, respectively without significant yield loss compared to CF condition. Although AWD irrigation increased cumulative N2O emissions by 73%, it reduced the total global warming potential by 27% compared to CF irrigation. The CH4 emission factor for AWD was lower (1.67 kg ha−1 day−1) compared to CF (2.33 kg ha−1 day−1). Across the irrigation regimes, UDP increased rice yield by 21% and N recovery efficiency by 58% compared to PU. These results suggest that both UDP and AWD irrigation might be considered as a carbon-friendly technology.

Biochar and Compost-Based Integrated Nutrient Management: Potential for Carbon and Microbial Enrichment in Degraded Acidic and Charland Soils

Soil acidification and charland formation through alluvial sand deposition are emerging threats to food security in Bangladesh in that they endanger crop production in about 35% of its territory. The integrated plant nutrient system (IPNS) is a globally accepted nutrient management approach designed to revive the damaged soils’ fertility level. Total organic carbon (TOC) in soil is a composite index of soil quality that has consequences for agricultural productivity and natural soil ecosystems. This study assesses the impacts of using biochar, compost, poultry litter, and vermicompost-based IPNS approaches on labile and TOC pools, TOC stocks, lability and management indices, and microbial populations under different cropping patterns after 2 years in acidic and charland soils. The application of IPNS treatments increased microbial biomass carbon (MBC) by 9.1–50.0% in acidic soil and 8.8–41.2% in charland soil compared to the untreated soil, with the largest increase in poultry manure biochar (PMB). Microbial biomass nitrogen (MBN) rose from 20 to 180% in charland soil compared to the control, although no effect was observed in acidic soil. Basal respiration (BR) rose by 43–429% in acidic soil and 16–189% in charland soil compared to the control, exhibiting the highest value in PMB. IPNS treatments significantly improved SOC and POC but did not affect POXc and bulk density in both soils. The PMB and organic fertilizer (OF, compost)-based IPNS wielded the greatest influence on the lability index of MBC in acidic soils and the management index of MBC in both soils. This is despite the fact that IPNS did not affect the lability and management indices of active carbon (AC). IPNS treatments increased the stocks of SOC and MBC in both the soils and POC stock in acidic soil. IPNS treatments significantly boosted the bacterial and fungal populations in both soils, despite having no effect on phosphorus-solubilizing bacteria (PSB). Thus, PMB and OF (compost)-based IPNS may be a better nutrient management practice in degraded acidic and charland soils. This is especially the case in terms of soil quality improvement, soil carbon sequestration, and microbial enrichment.

Influence of Soil Test Crop Response Based Integrated Plant Nutrient Management on Quality of Okra [Abelmoschus esculentus (L.) Monech

In Soil Test Crop Response (STCR) based Integrated Plant Nutrient System (IPNS) technology, the fertilizer doses are tailored as per the requirements of estimated crop yield taking into account the nutrient requirement of the crop, and the contribution of nutrients from the soil, fertilizers and organic manures. In this study, a field experiment was carried out in the Bahour soil series of Puducherry to study the quality of Okra in response to STCR-based manure and fertilizer application. The experiment was carried out with ten treatments viz., farmer’s practice, FYM alone @ 12.5 t ha-1, blanket recommendation, STCR-NPK alone @ 160, 170, and 180 q ha-1, and STCR-IPNS @ 160, 170, and 180 q ha-1 and control replicated thrice. The fruit samples were collected at 5th, 12th, and 19th pickings and were analyzed for quality parameters. Application of STCR + IPNS – 180 q ha-1 improved the quality parameters such as mucilage (4.54%), protein (1.84%), and starch (4.95%) and ascorbic acid (13.99 mg per100g) content of Okra. The STCR-IPNS technology ensures sustainable crop production and economical use of expensive fertilizer.

Integrated Nutrient Management Enhances Productivity and Nitrogen Use Efficiency of Crops in Acidic and Charland Soils.

Integrated Plant Nutrient System (IPNS) is practiced worldwide to maintain soil quality. Two field experiments were conducted in 2019 and 2020 in acidic and charland soils to assess the impact of different manures, viz., poultry manure (PM), vermicompost (VC), compost (OF), rice husk biochar (RHB), poultry manure biochar (PMB)-based IPNS, and dolomite over control on productivity and nitrogen use efficiency (NUE) of the Mustard-Boro-Transplanted Aman and Maize-Jute-Transplanted Aman cropping patterns, and on soil properties. The experiments were laid out in a randomized complete block design with four replications. The results showed that IPNS treatments significantly improved soil aggregate properties and total nitrogen in acidic soil, and bulk density in charland soil. In both years, IPNS treatments increased system productivity from 55.4 to 82.8% in acidic soil and from 43.3 to 115.4% in charland soil over that of control. IPNS and dolomite treatments increased nitrogen uptake from 35.5 to 105.7% over that of control and NUE in both soils in 2019 and 2020. PMB- and OF-based INPS treatments exhibited superior performances in both soils, and the impact was more prominent in 2020. Therefore, PMB- and OF-based IPNS can be recommended for maximizing system productivity and NUE with concurrent improvement of physicochemical properties of acidic and charland soils.

Nitrogen Release in Soils Amended with Different Organic and Inorganic Fertilizers under Contrasting Moisture Regimes: A Laboratory Incubation Study

Understanding nitrogen (N) release patterns and kinetics is a key challenge for improving N use efficiency in any agroecosystem. An incubation experiment was done to study the N release pattern and kinetics of contrasting soils amended with compost (CO), poultry manure (PM), rice husk biochar (RHB), poultry manure biochar (PMB) and cowdung (CD) combined with chemical fertilizer (integrated plant nutrient system, IPNS approach) under two moisture regimes, viz. field capacity (FC) and continuous standing water (CSW) at 25 °C for 120 days. Our results revealed that NH4+-N was the dominant under CSW conditions, whereas NO3−-N was dominant under FC conditions. Net mineral N data fitted well to the first order kinetic model. Both N release potential (N0) and rate constant (k) were greater in acidic soil than those of charland soil. The maximum N release varied between 24.90–76.29% of input depending on soil type and moisture status. N mineralization was strongly correlated with urea N application. PM and PMB mineralized in all soil and moisture conditions whereas N immobilization was observed in the case of RHB. N mineralization was strongly correlated with urea N application. Gaseous N losses were different for the organic amendments exhibiting more gaseous N losses in PM, CD and CO based IPNS whereas the lowest gaseous N loss was observed in PMB based IPNS. Biochar based IPNS increased soil pH in all conditions. Thus, the present study suggests that N release depends on soil type, soil moisture and type of organic amendment. However, CO, PM and CD based IPNS can be recommended for both acidic and charland soils in terms of N release as short duration crops will suffer from N deficiency if biochar based IPNS is used in the field.

Emission factors and global warming potential as influenced by fertilizer management for the cultivation of rice under varied growing seasons

Greenhouse gas (GHG) emissions from paddy fields are intensified during rice production, and are generally reported based on single or double cropping. It needs to be known how emission factors, GHG emission patterns, and global warming potential are affected by growing three rice crops yearly under the principle of integrated plant nutrient system fertilization (IPNSF). Cowdung and vermicompost were used as IPNSF and compared with commercial fertilization alone. A static close chamber technique was used to measure GHG emissions. The peak periods of CH4 emissions were 20–37, 22–42, and 19–38 days after transplanting during dry, wet, and premonsoon seasons, respectively. The use of cow dung significantly enhanced total N2O, CH4, and CO2 fluxes by 5–10%, 15–23%, and 9–20%, respectively, compared to vermicompost. CH4 emissions for each kg grain production were 39–80, 45–63, and 43–57 gm in the dry, premonsoon, and wet seasons, respectively. Vermicompost significantly reduced CH4, CO2, and N2O fluxes by 13–19%, 17–21%, and 4–9%, respectively, along with a reduction in GHG emission factors by 8–17% and global warming potential by 13–17% compared to cow dung. Moreover, vermicompost and cow dung significantly improved rice grain yields in all three growing seasons compared to commercial fertilizer alone. In conclusion, the use of vermicompost as an IPNSF could be a viable technique for improving grain yield and for reducing GHG emissions from paddy fields during year-round rice cultivation.

Effect of Integrated Plant Nutrient System on Selected Medicinal Plant - Tulsi (Ocimum sanctum)

Effect of Integrated Plant Nutrient System on Selected Medicinal Plant - Tulsi (Ocimum sanctum)

Effect of integrated plant nutrient system on phosphorus solubilisation and productivity of wheat in vertisols

The present investigation in relation to “Effect of integrated plant nutrient system on phosphorus solubilisation and productivity of wheat in Vertisols” was conducted during rabi season of 2019-20 at Botany Research Farm, College of Agriculture, Nagpur. The results revealed that the use of ghanjivamrut @ 5 t ha-1 at incorporation of green manuring in combination with 50 % RD of chemical fertilizers + bio-fertilizers is the suitable nutrient source for maintaining soil available phosphorus nutrient at physiological growth stage and fertility status and it also improve the uptake of nutrient and yield of wheat. The grain yield of wheat was 3.63, 4.52 and 14.40 per cent higher over 100 % RDF + GM with the IPNS practice, there by 50 % chemical fertilizers can be saved and increase solubility.

Effect of varying fertilizer doses and soil test crop response based integrated plant nutrient system on enzyme activity in Bahour soil series of Puducherry

An incubation experiment was conducted during Kharif, 2018 on bahour soil series of puducherry to study the influence of various fertilizer doses and Soil Test Crop Response (STCR) based Integrated Plant Nutrient System (IPNS) on soil enzymatic activity. The incubation experiment was carried out with ten treatments and three replications. The soil samples were drawn at 0th, 40th and 80th day of incubation and subjected for urease, phosphatase and dehydrogenase enzyme analysis. The results revealed that the application of STCR + IPNS – 180 q ha-1 treatment has improved the activities of Urease (12.08 µg NH4- N g-1h-1), Phosphatase (13.65µg PNP g-1h-1) and dehydrogenase (2.48µg TPF g-1day-1). All the three enzymes activities were increased from the Initial day of incubation to 40th day and later showed decrease at final days.

Long term effect of nitrogen fertilization on yield and soil fertility status of rainfed cotton under vertisols track of Southern district

A field experiment was conducted in the Agricultural Research Station, Kovilpatti under dryland situation from 2011-‘19 to find out the long term effect of nutrient and combined effect of organic and inorganic nutrients on crop yield and soil fertility status in cotton crop. This experiment was conducted in randomized block design replicated thrice under rainfed situation. The characteristics of the experimental soil was clay in texture and belongs to Kovilpatti Soil Series (Typic Chromusterts). The soil pH was towards alkaline in nature. The available nutrient status of the soil was low in available nitrogen, low to medium in available phosphorus and high in available potassium content. The treatment comprised of nine treatments. T1 - Control, T2 - 100% RDF (40:20:40 NPK kg ha-1), T3- 50% RDF (20:10:20 NPK kg ha-1), T4- 50% N (crop residues), T5 -50% N (FYM), T6 - 50% Inorganic N+ 50% organic N (crop residues) + P (50%) + K (50%), T7 -50% inorganic N+ 50% organic N (FYM) + P (50%) + K (50%), T8 -100% RDF + 25 kg ZnSO4 ha-1 and T9 - FYM @ 12.5 ha-1. The results revealed that among the different treatment schedule over the long term basis, application of 100% RDF + 25 kg ZnSO4 ha-1 registered higher number of sympodial branches/plant (19.3 no’s), number of bolls/plant (15.0 no’s), boll weight (3.4 g) and seed cotton yield (1277 kg ha-1), net income (Rs.24868/ha), B:C (1.76) and RWUE (3.4 kg/ha mm). Soil fertility status also has been increased over the years by the supply of nutrients through integrated plant nutrient system (IPNS) approach.

Carbon sequestration in paddy soil as influenced by organic and inorganic amendments

Rice plants mediate carbon (C) emission from paddy soils but also absorb it as carbon dioxide (CO2) during photosynthesis. This means that net C emission could vary depending on rice cultivation techniques, which is not well documented in Asian regions. In the present investigation, the effect of different C sources on major greenhouse gas (GHG) fluxes and their relationships between C inputs and outputs were established by using closed static chamber technique. Total methane (CH4), nitrous oxide (N2O) and CO2 emissions were significantly higher with integrated plant nutrient system (IPNS) based fertilization with cowdung (CD), poultry manure (PM) and vermicompost (VC) than chemical fertilizer alone. Net ecosystem C budget (NECB) was positive with CD-IPNS (52–54 kg C ha−1), PM-IPNS (62–64 kg C ha−1) and VC-IPNS (53–56 kg C ha−1) but negative with chemical fertilization (−7 to −8 kg C ha−1). In control and chemical fertilizer treatments, net CO2 sequestration was negative (−602 and −87 kg CO2 ha−1), but organic amendments showed positive CO2 sequestration that varied from 68 to 94 kg CO2 ha−1 during the study periods. Organic amendment significantly improved CO2 capturing capacity by about 17–22 gm kg−1 grain yield compared to chemical fertilization (−24 to −25 gm kg−1). Rice yield also enhanced by about 14–23% with organic amendments compared to chemical fertilizer treatment. In conclusion, use of organic C sources would be very valuable practice to increase net CO2 sequestration and wet season rice yield under tropical climatic conditions.

Integrated Effects of Poultry Manure and Chemical Fertilizer on Yield, Nutrient Balance and Economics of Wetland Rice Culture

Field trials were conducted for two years to evaluate the integrated effect of poultry manure (PM) and chemical fertilizers on yield, nutrient balance and economics of rice at BRRI, Gazipur (AEZ-28 and land type- High Land) during Boro 2009 to T. Aman 2010. Eight treatment combinations, where PM @ 1, 2, 3 t ha-1 with IPNS (Integrated plant nutrient system) based dose and PM @ 1, 2, 3 t ha-1 with 50% STB (soil test based) dose along with a control and 100% STB chemical fertilizer were tested. Immediate effects of manure and fertilizer were evaluated in Boro season and residual effects were observed in the following T. Aman season. Application of PM @ 2 t ha-1 with IPNS based chemical fertilizer or PM @ 3 t ha-1 with 50% STB dose gave higher grain yield in Boro season. Some residual effects in the succeeding T. Aman rice were observed where PM was used @ 3 t ha-1. The highest net return was obtained with 3 t PM ha-1 with 50% STB dose. A positive nutrient balance of phosphorus and sulfur were observed in PM and chemical fertilizer treated plots.&#x0D; Bangladesh Rice j. 2018, 22(2): 71-77

Participation of Rural Women in Homestead Waste Management towards Integrated Plant Nutrient System (IPNS)

The main purpose of this study was to assess the extent of participation in homestead waste management activities by the rural women towards Integrated Plant Nutrient System (IPNS). Besides this major focus, the sources of homestead wastes and their channels of utilization were identified; and relationship between the selected characteristics of the rural women and their extent of participation in homestead waste management activities were also explored. All the women of farm household except the absentees of Babugonj upazila of Barisal district, Bangladesh constituted the population of the study. Data were collected from the sample of 95 farm households selected out of a total of 1000 farm households from the five (5) selected villages under the one (1) selected union of the upazila through multi-stage random sampling technique with the help of pre-tested interview schedule during from the period from 10 August to 20 September 2017. A vast majority of the respondents had medium to high participation in homestead waste management activities in the study area while their efforts were mostly diverted to kitchen wastes, plant/crop harvest residues and ash management. The correlation test showed that rural women’s personal education, farm size, annual household income, family cooperation, daily time allocation for homestead waste management, exposure to agricultural information and seasonal variability of involvement in waste management activities showed significant positive relationship with their extent of participation in homestead waste management activities. While age, family size, area under homestead, perception of IPNS, awareness of environmental degradation and decision making ability in family did not show any significant relationship with their extent of participation in waste management activities.