Nutrient dynamics,dehydrogenase activity,and response of the rice plant to fertilization sources in an acid lateritic soil

Abstract

Rice variety IR 36, grown under flooding, was studied in 1998 to determine the effects of fly ash, organic, and inorganic fertilizers on changes in pH and organic carbon, release of nutrients (NH₄ ⁺-N, Bray's P, and NH₄OAc K), and dehydrogenase activity in an acid lateritic soil at 15-day intervals. Application of fly ash at 10?t?ha^?1 alone did not improve the availability of NH₄ ⁺-N, or P, as well as the rice grain yield. Availability of NH₄ ⁺-N (35.3–36.9?mg?kg^?1), and P (12.3–14.6?mg?kg^?1) at 15 days after transplanting, and rice grain yields (48.0–51.7?g per pot) were similar under the various fertilization sources such as inorganic fertilizer alone, inorganic fertilizer?+?fly ash or inorganic fertilizer?+?green manure?+?fly ash. Mean dehydrogenase activity was the highest (8.47?µg triphenyl formazon g^?1 24?h^?1) under the mixed fertilization treatments with green manure. At the end of the cropping season (75 days after transplanting), pH, organic carbon, and dehydrogenase activity were higher under the mixed fertilization treatments involving green manure by 3, 15 and 154%, respectively, compared with the inorganic fertilizer alone.     

Nitrogen and phosphorous fertilizer improve pastures naturally growing under hazelnut trees

Abstract

This three-year study (2003–2005) aimed to improve the yield and quality of pastures growing naturally that are colonized by naturally occurring vegetation without agricultural input under hazelnut (Corylus sp.) orchards in the middle and eastern Black Sea regions of Turkey. There were eight treatments: 1) control; 2) fertilizer only (triple superphosphate 44% and calcium ammonium nitrate 26%) (80kg ha^?1 P and 60 kg ha^?1 N in Samsun; 100 kg ha^?1 P and 80 kg ha^?1 N in Ordu; 100 kg ha^?1 P and 40 kg ha^?1 N in Giresun); 3) lime only (calcium carbonate 94%) (3.0 t ha^?1 lime in Samsun; 4.5 t ha^?1 lime in Ordu and Giresun); 4) early cut only; 5) soil aeration only; 6) fertilizer+lime; 7) fertilizer+lime+early cut; 8) fertilizer+lime+soil aeration, laid out in a randomized complete block design with four replicates at each location. The highest dry matter (DM) yield of kg ha^?1 and crude protein content (%) was obtained from the treatments that included fertilizer. There was no difference in DM production between any of the combination treatments that involved fertilizer and the fertilizer alone treatment. Only lime and aeration applications also increased yield compared to control, but not as much as did any treatment including fertilizer. Crude protein content of the pasture ranged from 13.3 to 18.1% across locations. Nitrogen and phosphorus fertilizer are recommended to improve DM yields and herbage quality for pastures under hazelnut orchards.     

Eucalyptus biochar application enhances Ca uptake of upland rice,soil available P,exchangeable K,yield, and N use efficiency of sugarcane in a crop rotation system

It was hypothesized that the application of eucalyptus biochar enhances nutrient use efficiencies of simultaneously supplied fertilizer, as well as provides additional nutrients (i.e., Ca, P, and K), to support crop performance and residual effects on subsequent crops in a degraded sandy soil. To test this hypothesis, we conducted an on‐farm field experiment in the Khon Kaen province of Northeastern Thailand to assess the effects of different application rates of eucalyptus biochar in combination with mineral fertilizers to upland rice and a succeeding crop of sugarcane on a sandy soil. The field experiment consisted of three treatments: (1) no biochar; (2) 3.1 Mg ha^?1 biochar (10.4 kg N ha^?1, 3.1 kg P ha^?1, 11.0 kg K ha^?1, and 17.7 kg Ca ha^?1); (3) 6.2 Mg ha^?1 biochar (20.8 kg N ha^?1, 6.2 kg P ha^?1, 22.0 kg K ha^?1, and 35.4 kg Ca ha^?1). All treatments received the same recommended fertilizer rate (32 kg N ha^?1, 14 kg P ha^?1, and 16 kg K ha^?1 for upland rice; 119 kg N ha^?1, 21 kg P ha^?1, and 39 kg K ha^?1 for sugarcane). At crop harvests, yield and nutrient contents and nitrogen (N) use efficiency were determined, and soil chemical properties and pH₀ monitored. The eucalyptus biochar material increased soil Ca availability (117 ± 28 and 116 ± 7 mg kg^?1 with 3.1 and 6.2 Mg ha^?1 biochar application, respectively) compared to 71 ± 13 mg kg^?1 without biochar application, thus promoting Ca uptake and total plant biomass in upland rice. Moreover, the higher rate of eucalyptus biochar improved CEC, organic matter, available P, and exchangeable K at succeeding sugarcane harvest. Additionally, 6.2 Mg ha^?1 biochar significantly increased sugarcane yield (41%) and N uptake (70%), thus enhancing N use efficiency (118%) by higher P (96%) and K (128%) uptake, although the sugar content was not increased. Hence, the application rate of 6.2 Mg ha^?1 eucalyptus biochar could become a potential practice to enhance not only the nutrient status of crops and soils, but also crop productivity within an upland rice–sugarcane rotation system established on tropical low fertility sandy soils.     

Coal Fly Ash and Phospho‐gypsum Mixture as an Amendment to Improve Rice Paddy Soil Fertility

Abstract

Rice is a plant that requires high levels of silica (Si). As a silicate (SiO₂) source to rice, coal fly ash (hereafter, fly ash), which has an alkaline pH and high available silicate and boron (B) contents, was mixed with phosphor‐gypsum (hereafter, gypsum, 50%, wt wt^?1), a by‐product from the production of phosphate fertilizer, to improve the fly ash limitation. Field experiments were carried out to evaluate the effect of the mixture on soil properties and rice (Oryza sativa) productivity in silt loam (SiL) and loamy sand (LS) soils to which 0 (FG 0), 20 (FG 20), 40 (FG 40), and 60 (FG 60) Mg ha^?1 were added. The mixture increased the amount of available silicate and exchangeable calcium (Ca) contents in the soils and the uptake of silicate by rice plant. The mixture did not result in accumulation of heavy metals in soil and an excessive uptake of heavy metals by the rice grain. The available boron content in soil increased with the mixture application levels up to 1.42 mg kg^?1 following the application of 60 Mg ha^?1 but did not show toxicity. The mixture increased significantly rice yield and showed the highest yields following the addition of 30–40 Mg ha^?1 in two soils. It is concluded that the fly ash and gypsum mixture could be a good source of inorganic soil amendments to restore the soil nutrient balance in rice paddy soil.     

Integrated Fertilizer Management: Influence on Soil Nitrogen,Available Phosphorus,Potassium, Nutrient Uptake and Maize Yield

A field experiment was conducted on an Alfisol (kandic paleustalf) in Abeokuta, Southwestern Nigeria, for two seasons to assess the influence of inorganic and organic fertilizers on nitrogen (N), phosphorus (P), potassium (K), nutrient uptake and maize yield. The treatments consisted of three rates of organic fertilizer 0, 5 and 10 t ha^?1 in the form of poultry manure and NPK fertilizer (20:10:10) applied at 0 and 120 kg ha^?1. Maize (Zea mays) was used as the test crop. The results showed that the combined application of 10 t ha^?1 poultry manure and 120 kg ha^?1 NPK fertilizer enhanced the uptake of N, P and K better than other treatment combinations. Application of 10 t ha^?1 poultry manure alone gave the highest grain yield, which was 67.02% higher than the control in the first season. Complementary application of 5 t ha^?1 poultry manure with 120 kg ha^?1 NPK 20–10-10 was recommended for grain yield.     

Nutrient‐enriched soils and native N‐fixing plants in New Zealand

Approximately 40% of New Zealand's land mass is fertilized grassland with entirely non‐native plants, but currently there is substantially increased interest in restoration of native plants into contemporary agricultural matrices. Native vegetation is adapted to more acid and less fertile soils and their establishment and growth may be constrained by nutrient spillover from agricultural land. We investigated plant–soil interactions of native N‐fixing and early successional non N‐fixing plants in soils with variable fertility. The effects of soil amendments of urea (100 and 300 kg N ha^?1), lime (6000 kg CaCO₃ ha^?1), and superphosphate (470 kg ha^?1) and combinations of these treatments were evaluated in a glasshouse pot trial. Plant growth, soil pH, soil mineral N, Olsen P and nodule nitrogenase activity in N‐fixing plants were measured. Urea amendments to soil were not inhibitory to the growth of native N‐fixing plants at lower N application rates; two species responded positively to combinations of N, P and lime. Phosphate enrichment enhanced nodulation in N‐fixers, but nitrogen inhibited nodulation, reduced soil pH and provided higher nitrate concentrations in soil. The contribution of mineral N to soil from the 1‐year old N‐fixing plants was small, in amounts extrapolated to be 10–14 kg ha^?1 y^?1. Urea, applied both alone and in conjunction with other amendments, enhanced the growth of the non N‐fixing species, which exploited mineral N more efficiently; without N, application of lime and P had little effect or was detrimental. The results showed native N‐fixing plants can be embedded in agroecology systems without significant risk of further increasing soil fertility or enhancing nitrate leaching.     

System productivity,nutrient use efficiency and apparent nutrient balance in rice-based cropping systems

A 2-year field experiment was conducted to assess system productivity, nutrient use efficiency and apparent balances of phosphorus (P) and potassium (K) in diversified rice-based cropping systems at Gazipur, Bangladesh. Four cropping systems: wheat–fallow–rice, maize–fallow–rice, potato–fallow–rice and mustard–fallow–rice in main plots and four nutrient combinations: NPK, NK, NP and PK in sub-plots were arranged in a split-plot design with three replications. Receiving the NPK treatment, all the component crops gave the highest yield, and omission of N from fertilizer package gave the lowest yield. The maize–rice system removed the highest amount of N (217 kg ha^?1), P (41 kg ha^?1) and K (227 kg ha^?1) followed by wheat–rice, potato–rice and the least in mustard–rice system. The wheat–rice and maize–rice system showed negative K balance of –35.5 and –60.4 kg ha^?1 in NPK treatment, while potato–rice system showed a positive K balance of 31.0 kg ha^–1 with NPK treatment. The N, P and K uptake and apparent recovery by the test crops may be used for site-specific nutrient management. The K rates for fertilizer recommendation in wheat and maize in Indo-Gangetic plain need to be revised to take account for the negative K balance in soil.     

Long-term fertilizer trials on loam soil at M⊘ystad,south-eastern Norway: Crop yields,nutrient balances and soil chemical analyses from 1983 to 2003

Abstract

Factorial combinations of N, P and K fertilizer have been compared with the use of farmyard manure at M?ystad since 1922 in a seven-year crop rotation (3 ley, oat, potato, wheat, barley). Until 1982, low inputs of N fertilizer (22 kg ha^?1) were used. In 1983, they were brought into line with current farming practice. This paper presents the results of three subsequent rotations. Yields without any fertilizer were on average 48% of those with 100 kg N ha^?1 in compound fertilizer, whilst those with 20, 40 and 60 Mg ha^?1 farmyard manure were 81, 87 and 90%, respectively. Yields with other combinations of N, P and K declined in the order NP, NK, N, PK and K. When NPK fertilizer was used, apparent recoveries of applied fertilizer were close to 50% for N and K, and around 40% for P. Much lower values were found for nutrients applied singly. Balance between N supply and removal was indicated at rates of about 60 kg N fertilizer ha^?1 in potatoes, 75 kg ha^?1 in cereals and 90 kg ha^?1 in leys. A surplus of P was found in all crops at all N levels, and of K in cereals and potatoes. In leys, K balance was achieved with an N supply of 90 kg N ha^?1. Nutrient balance was indicated at a little below 20 Mg ha^?1 yr^?1 farmyard manure. Larger manure applications gave large nutrient surpluses, particularly of N. Soil reaction remained close to neutral with the use of calcium nitrate and manure, but declined with the use of ammonium nitrate. Manure use gave the highest amounts of available P, K and Mg in soil. Similar increases in total inorganic P were found with manure use as with fertilizer use, but amounts of organic P and total K were little affected.     

Relative effect of organic and conventional farming on growth,yield and grain quality of scented rice and soil fertility 1 : Relative wirkung von organischem und konventionellem ackerbau auf wachstum,ertrag und kornqualität von reis und auf die bodenqualität

A field experiment was conducted during the kharif season of the crop year 2001 at the Indian Agricultural Research Institute, New Delhi, to study the comparative effects of organic and conventional farming on scented rice. Grain yield of rice increased significantly with increasing rate of fertilizer application only up to 60?kg N?+?13?kg P?+?17?kg K ha^???1. The effect of 10 t ha^???1 farmyard manure (FYM) was found to be similar to 60?kg N?+?13?kg P?+?17?kg K ha^???1, whereas the effect of Sesbania green manuring (SGM) was similar to 120?kg N?+?26?kg P?+?34?kg K ha^???1. Inoculation of BGA (Blue green algae) with FYM or SGM had no additional advantage over FYM or SGM alone. The highest yield (5.2 t/ha) of rice was obtained when FYM?+?SGM?+?BGA?+?PSB (Pseudomonas striata) were applied together. The yield obtained with this combination was significantly more than that obtained with 180?kg N?+?39?kg P?+?51?kg K ha^???1. A similar trend was observed in N, P, and K uptake of rice. Inorganic nutrients had no significant effect on grain quality parameters like head rice recovery (HRR), kernel length (KL), kernel breadth (KB) and KL?:?KB ratio, whereas organic manures and biofertilizers resulted in an increase in HRR, KL and KL?:?KB ratio. A combination of FYM?+?SGM?+?BGA?+?PSB also resulted in highest organic C and available N content in soil and thus holds a promise for sustainable production.     

Effect of Vermicompost and Chemical Fertilizer on Growth,Herb, Oil Yield,Nutrient Uptake,Soil Fertility,and Oil Quality of Rosemary

Essential oil of rosemary (Rosmarinus officinalis L.) possesses good olfactory properties and is suitable for use in perfumes, soaps, and fragrances. Field experiments were conducted for 2 years (2003?2005) in an area experiencing a semi-arid tropical climate to study the influence of vermicompost and chemical fertilizer on growth, herb, oil yield, nutrient uptake, soil fertility, and oil quality of rosemary. Results from the experiment revealed that among the seven treatments, the application of vermicompost (8 t ha^?1) + fertilizer nitrogen (N)?phosphorus (P)??potassium (K) (150:25:25 kg ha^?1) produced optimum herbage and oil yield of rosemary compared with control (no fertilizer) and was found to be on par with application of fertilizer NPK 300:50:50 kg ha^?1. Content and quality of oil were not influenced by vermicompost and chemical fertilizers. Furthermore, it was noticed that available N and P were greater in postharvest soils that received vermicompost alone or in combination with inorganic fertilizers than control (no fertilizer) and inorganic fertilizer?treated soil. This study indicates that combined application of vermicompost and chemical fertilizer helps to increase crop productivity and sustain the soil fertility.     

Soil-Test-Based Optimum Fertilizer Doses for Attaining Yield Targets of Rice under Midland Alfisols of Eastern India

Soil-test crop-response experiments on rice were conducted in the Bastar Plateau Agroclimatic Zone of Chhattisgarh during 2009–2011 to assess yield, soil, plant, and fertilizer nitrogen (N), phosphorus (P), and potassium (K) nutrient relationships and calibrate optimum fertilizer doses for attaining yield targets. Soil fertility status was poor to medium for N (194–283 kg ha^?1) and P (7.53–19.66 kg ha^?1), and medium to good for K (226–320 kg ha^?1). Based on nutrient requirements (NR, kg q^?1) and contributions from soil (CS, %), fertilizer (CF, %), and farmyard manure (CFYM, %), optimum fertilizer doses were derived. The fertilizer doses were validated for attaining yield targets of 5000 and 6000 kg ha^?1 in farmer’s fields. Rice yield within 10% deviation was attained, which indicated that soil-test-based fertilizer dose was superior. This approach could be adopted for regions with similar soil and agroclimatic conditions in other parts of the world to increase rice yields.     

Effect of Integrated Nutrition in Aromatic Rice on Carbon and Nutrient Status in an Inceptisol

Inorganic fertilizer-based nutrient management is the maintenance of soil fertility for sustaining increased crop productivity, but often at the cost of degrading soil health. This study was conducted to determine whether incorporation of organics in the conventional inorganic-based nutrient management practice on aromatic rice could sustain both fertility and soil organic carbon status on a silt loam Aeric Haplaquept. Addition of organic manure along with inorganic fertilizer could almost maintain organic carbon status of soil, while the treatment only with inorganic fertilizer registered a substantial decrease (6.58%) from its initial value. Among the treatment combinations, the treatment receiving 1 t ha^?1 mustard cake and inorganic fertilizer @ N₄₀P₂₀K₂₀ was the best, which registered the highest grain (3.01 t ha^?1) and straw (5.32 t ha^?1) yield of rice, highest nutrient uptake, and least decline in available N, P, and K status of soil. However, even the best treatment combination also was proved to be suboptimal in sustaining soil fertility.     

Effect of addition of organic residues,farmyard manure and fertilizer nitrogen on soil fertility in rice‐wheat cropping system

A field experiment was conducted for 3 crop years (July‐June) at the Indian Agricultural Research Institute, New Delhi to study the effects of Sesbania and cowpea green manuring (GM) and incorporation of mungbean residues after harvesting grain, Leucaena loppings, FYM and wheat straw incorporation before planting rice and application of 0,40,80 and 120 kg N ha^?1 to rice on the soil organic carbon (SOC), alkaline permanganate oxidizable N (APO‐N), 0.5 M sodium bicarbonate extractable P (SBC‐P) and 1N ammonium acetate exchangeable K (AAE‐K) in surface 0–15 cm soil after the harvest of rice and wheat grown in sequence. Green manuring and addition of organic residues prevented the decline in SOC. On the other hand addition of N fertilizer tended to decrease SOC after rice harvest. On the contrary application of green manures, organic residues, FYM and fertilizer N increased APO‐N, which indicates the benefit of these treatments to a more labile soil organic N pool. Also application of green manures, organic residues, FYM and fertilizer N increased SBC‐P. Not much change was observed in AAE‐K by the treatments applied.     

Application rate and composting method affect the immediate and residual manure fertilizer value in a maize–rice–rice–maize cropping sequence on a degraded soil in northern Vietnam

A field experiment was carried out in northern Vietnam to investigate the effects of adding different additives [rice (Oriza sativa L.) straw only, or rice straw with added lime, superphosphate (SSP), urea or a mixture of selected microorganism species] on nitrogen (N) losses and nutrient concentrations in manure composts. The composts and fresh manure were applied to a three-crop per year sequence (maize–rice–rice) on a degraded soil (Plinthic Acrisol/Plinthaquult) to investigate the effects of manure type on crop yield, N uptake and fertilizer value. Total N losses during composting with SSP were 20% of initial total N, while with other additives they were 30–35%. With SSP as a compost additive, 65–85% of the initial ammonium-N (NH₄-N) in the manure remained in the compost compared with 25% for microorganisms and 30% for lime. Nitrogen uptake efficiency (NUE) of fresh manure was lower than that of composted manure when applied to maize (Zea mays L.), but higher when applied to rice (Oriza sativa L.). The NUE of compost with SSP was generally higher than that of compost with straw only and lime. The mineral fertilizer equivalent (MFE) of manure types for maize decreased in the order: manure composted with SSP?>?manure composted with straw only and fresh manure?>?manure composted with lime. For rice, the corresponding order was: fresh manure?>?manure composted with SSP/microorganisms/urea?>?manure composted with lime/with straw alone. The MFE was higher when 5 tons manure ha^?1 were applied than when 10 tons manure ha^?1 were applied throughout the crop sequence. The residual effect of composted manures (determined in a fourth crop, with no manure applied) was generally 50% higher than that of fresh manure after one year of manure and compost application. Thus, addition of SSP during composting improved the field fertilizer value of composted pig manure the most.     

Cumulative Effect of Organic and Inorganic Sources of Nutrients on Yield,Nutrients Uptake and Economics by Rice–Wheat Cropping System in Indo-Gangetic Plains of India

ABSTRACT

Field experiments were conducted for 2 years in sandy loam soil, to study the direct effect of organic manures i.e. sewage sludge (SS), vermicompost (VC) and sesbania (SB) and chemical fertilizers on rice (Oryza sativa) and their residual effect on wheat (Triticum aestivum) grown in sequence in winter (Rabi) and summer (Kharif) season during 2015–2016 to 2016–2017 at Varanasi, Uttar Pradesh. Residual effect of organic sources of nutrients as SS, VC and SB were monitored up to fourth crop (II wheat) in sequence applied in conjunction with 75% recommended dose of fertilize (RDF). Among the nutrient sources, the maximum grain yield in I rice (4.89 t ha^?1), II rice (4.95 t ha^?1), was recorded in treatment T₃ (100% RDF with S, Zn, B) whereas in I wheat (4.68 t ha^?1) and II wheat (4.59 t ha^?1), it was recorded in T₄ (customized fertilizer). The maximum straw yield during all four crops was recorded in T₃ (100% RDF with S, Zn, B) in rice and T₄ (customized fertilizer) in wheat crop, which showed 25, 32, 23 and 28% increase over 100% RDF (T₂). Application of 100% RDF along with S, Zn, B and customized fertilizer increased the total uptake of N, P, K, S and B and also in net returns and B:C ratio followed by organic treatments.     

N and P losses from a paddy field plot in central Korea

Abstract

The study was carried out to investigate the water balance and runoff and infiltration losses of nutrients in a paddy field plot located in southern Korea. Field monitoring was carried out during the cropping season from May 1, 1999 to September 30, 2000. The soil of the experimental paddy field belonged to the Jisan series (SiL; fine loam, mixed, mesic Fluventic Haplaquepts) covering on area of 5,000 m² (100 m × 50 m). The measured input quantities of N and P into the paddy field were as follows: 122 and 140 kg N ha^?1 and 29 and 30 kg P₂O₅ kg ha^?1 from chemical fertilizer, 20 and 28 kg N ha^?1 and 0.35 and 0.36 kg P ha^?1 from precipitation, and 26 and 35 kg N ha^?1 and 0.57 and 0.72 kg P ha^?1 from irrigation water, respectively. The measured outputs of N and P during the study period were as follows: 48 and 52 kg N ha^?1 and 1.1 and 1.6 kg P ha^?1 from runoff water, and 9 and 12 kg N ha^?1 and 0.04 and 0.05 kg P ha^?1 from infiltration. The runoff loading was the highest in June, presumably because of the higher concentrations of chemical components associated with chemical fertilizer application. The runoff losses of nutrients were compared to the amounts of nutrients supplied by chemical fertilizers. It was found that the losses of N accounted for 34.3 and 42.6% of the chemical fertilizer applied, while those of P accounted for 3.8 and 5.3%. The ratio between nutrient losses by infiltration and the chemical fertilizer applied was 6.4 and 9.8% for N and 0.1 and 0.2% for P, respectively.     

Long-Term Effect of Fertilizers and Amendments on Depth-Wise Distribution of Available NPK,Micronutrient Cations,Productivity, and NPK Uptake by Maize-Wheat System in an Acid Alfisol of NorthWestern Himalayas

The present study was undertaken in the ongoing long-term fertilizer experiment initiated during 1972 at experimental farm of Department of Soil Science, Himachal Pradesh Agricultural University, Palampur (India). Soil samples collected from three depths (0–0.15, 0.15–0.30, and 0.30–0.45 m) were analyzed for pH; organic carbon; CEC; available N, P, and K; and micronutrients cations. Continuous use of optimal dose of fertilizers and FYM-influenced pH, organic carbon, CEC, available NPK, and DTPA extractable micronutrient cations significantly. The contents of organic carbon, available N, P, K, Fe, Mn, Zn, and Cu were higher in top soil layer (0–0.15 m) compared to lower depths (0.15–0.30 and 0.30–0.45 m). Highest productivity of wheat (89.89 q ha^?1) and maize (156.52 q ha^?1) was recorded under 100% NPK + FYM, which was at par with 100% NPK + lime. Application of 100% NPK along with amendments (FYM/lime) recorded significantly higher NPK uptake over other treatments.     

Organic Lettuce Growth And Nutrient Uptake Response To Lime,Compost And Rock Phosphate

Fertilizer recommendations are needed to increase organic vegetable yields. Thus, organic lettuce growth and nutrient uptake was investigated in a randomized block pot experiment with twelve treatments from the factorial structure of three factors: (i) Gafsa phosphate [0 and 200 kg phosphorus pentoxide (P₂O₅) ha^?1], (ii) compost from source separated municipal organic waste (0, 15, and 30 t ha^?1) and (iii) limestone [0 and 8 t ha^?1 calcium carbonate (CaCO₃) equivalent]. Lettuce yield increased with compost application and a first order interaction between lime and phosphate was clear because lime partially replaced the need for phosphate. This was explained by the effect of liming on P availability in acid soils. Nitrogen (N), phosphorus (P), and potassium (K) accumulation increased in lettuces produced with compost or phosphate but only the accumulation of N was increased with lime. This compost is recommended to increase nutrient availability for organic lettuce whereas the need for phosphate fertilization may decrease with liming.     

Pepper Response to Inorganic and Organomineral Fertilizers in Southwestern Nigeria

Information on the combination of organomineral fertilizer (OMF) and chemical fertilizer (CF) for pepper production is scarce. The effects of CF, OMF, and their combinations on pepper were studied in Abeokuta, Nigeria. In a screenhouse, 0, 2, 4, 6, 8, 10, 12, and 14 t ha^?1 OMF and 60 kg nitrogen (N) 19.8 kg phosphorus (P), and 39.6 kg potassium (K) ha^?1 CF were applied, and to the field 12 t ha^?1 OMF (100% OMF); 60 kg N 19.8 kg P, and 39.6 kg K ha^?1 (100% CF); OMF + CF (50:50); OMF + CF (25:75); and OMF + CF (75:25) were applied. Application of 12 t ha^?1 OMF (100% OMF) increased pepper yield and N, P, and K uptake in the screenhouse, whereas OMF + CF (75:25) promoted the yield of pepper in the field. Pepper could successfully be grown with either 12 t ha^?1 OMF or OMF + CF (75:25) with the type of soil used for this experiment.     

Influence of Long‐Term Application of Organic and Inorganic Fertilizer to Build Up Soil Fertility and Nutrient Uptake in Mint‐Mustard Cropping Sequence

Abstract

Field experiment was conducted for 7 years continuously to evaluate the influence of combined application of organic and inorganic fertilizer on soil fertility buildup and nutrient uptake in mint (Mentha arvensis) and mustard (Brassica juncea) cropping sequence. Maximum organic carbon was observed under full supply of organic manure (T₂; FYM at 20 t ha^?1) averaged across all the Stages of cropping sequence. It was increased by 38, 50, and 51% in T₂ in Stages I (after mint harvest/presowing of dhaincha), II (after incorporation of dhaincha (Sesbania aculeata)/presowing of mustard), and III (after harvest of mustard/preplanting of mint), respectively, over their respective controls. In general, magnitude of organic carbon was recorded higher in Stage II after green manuring of Sesbania compared with Stages I and III. Nitrogen availability in treated plots was increased by 26.0–89.9, 15.2–64.5, and 4.9–52.0% in Stages I (after mint harvest/presowing of Sesbania), II (after incorporation of dhaincha/presowing of mustard), and III (after harvest of mustard/preplanting of mint), respectively, over their respective control. Average across all the three Stages showed a positive balance of nitrogen (N), phosphorus (P), and potassium (K) in soil under different treatments. Mean of the three Stages indicated that maximum available N, P, and K were increased by 36.1, 129.0, and 65.20% in T₄ (N:P:K: 133:40:40 and FYM at 6.7 t ha^?1), T₄ (N:P:K::133:40:40 and FYM at 6.7 t ha^?1), and T₃ (N:P:K::100:30:30 and FYM at 10 t ha^?1), respectively, over their initial status. Supply of organic and inorganic fertilizer (T₄; N:P:K::133:40:40 and FYM at 6.7 t ha^?1) was found most suitable combination with respect to N, P availability in soil, and productivity of mint and mustard crop.