Relative Agronomic Efficiency Research Articles

Evaluación de rizobacterias promotoras del crecimiento bajo diferentes esquemas de fertilización en el cultivo de maíz variedad HIMECA-95

Bacteria previously isolated, characterized as diazotrophic and inorganic phosphate solubilizers were evaluated under field conditions as plant growth promoters on the maize production when soil fertility was changed. The strains MF1b and MF5, alone and in consortium, were inoculated on maize seeds (HIMECA-95), and these were sown under the following chemical fertility conditions: K, NK, PN, RK, NPK, and NRK (R: phosphate rock). Total dry weight, and N and P contents of the grain were determined at the end of the experiment; also, the % of relative agronomic efficiency (RAE) was calculated. Results showed that inoculation with the strain MF5 alone and in consortium, with the addition of NK fertilizer increased the % RAE in 130 and 403 for the dry weight, in 463 and 116 for the N content, and in 152 and 376 for the P content, respectively, allowing an increase in both production and grain quality. Moreover, it was observed variations among the evaluated parameters which could be related to the low N and P status of the soil, the soil fertility changes after the addition of the highly soluble chemical fertilizers, and the interaction between autochthonous microbial communities and the introduced

Comparative Effects of Soil Amendments on Phosphorus Use and Agronomic Efficiencies of Two Maize Hybrids in Acidic Soils of Molo County, Kenya

The deficiency of P and the shortened growing season s due to climate change are identified constraints in the production of commonly grown long maturing maize hybrid (H614) in the acid soils of Molo County , Kenya. The current studytherefore investigated(i) the effect of soil amendments; lime (L), minjingu phosphate rock (MPR) and manure (FYM) on soil available P and its uptake, phosphorus use efficiency (PUE) and maize grain yield of long (H614) and short (H513) maturing maize hybrids and (ii) the relative agronomic efficiency (RAE) of MPR. Field experiments were set up at the

Recovery of Essential Plant Nutrients from Biofuel Residual

Essential plant nutrients contained in residues and wastes generated during biofuel processing can be recovered for further production of bioenergy biomass. The objective of this study was to determine the relative agronomic efficiency of “processed” biofuel residual (PBR). Liquid biofuel residual was “processed” by precipitating phosphate and ammonium in the residual with magnesium into a struvite-like material. Then, in a series of greenhouse experiments, we evaluated the fertility potential of PBR, using sweet sorghum (Sorghum bicolor (L.) Moench), as a test bioenergy crop. We compared the agronomic effectiveness of PBR to inorganic commercial fertilizers, biosolids, and poultry manure as nutrient sources. The sources were either applied alone or in combination with supplemental essential plant nutrients (S, K, Mg, and micronutrients). In each of the greenhouse experiments, the crop was grown for 12 wk on soil of minimal native fertility. After each harvest, sufficient water was applied to the soil in each pot over a 6-wk period to yield ~2 L (~one pore volume) of leachate to assess potential total N and soluble reactive phosphorus (SRP) losses. Dry matter yields from the PBR treatment applied alone were significantly greater than yields from inorganic fertilizers, biosolids, and poultry manure treatments applied alone, and similar to yields obtained when the supplemental essential plant nutrients were added to the inorganic fertilizer, biosolids, and manure treatments. Leachate N and SRP concentrations from the PBR treatment were significantly lower than in the treatments with inorganic fertilizers, poultry manure, and biosolids. We conclude that PBR can substitute for inorganic fertilizers and other organic sources of plant nutrients to produce bioenergy biomass cheaply, without causing offsite N and P losses in vulnerable soils.

Response of Maize and Cowpea Grown Sequentially to Application of Phosphate Rock in the Humid Tropics

Field trials were conducted at the Institute of Agricultural Research and Training Ibadan in 2000 and 2001 cropping seasons to evaluate the efficiency of some phosphorus (P) sources, rates, and frequency of application on grain yields of maize and cowpea grown sequentially. The experiment was laid out in a split–split plot arrangement using randomized complete block design, with three replications. The main plot was frequency of fertilizer application (seasonal and annual). Source of P [single superphosphate (SSP: 18% P2O5)]; Ogun rock phosphate (OPR: 20.21% P2O5), and crystallizer super (CS: 31.4% P2O5) constituted the subplots. The P rates (0, 20, 40, and 60 kg P ha−1) were the sub-subplots. An early maize cropping followed by a late-season cowpea was the sequential cropping, while an early maize followed by a late-season maize was the continuous cropping. The croppings were repeated the second year. Frequency of P application and source of P were significantly different while rates of application were not. Maize and cowpea grain yields from the control treatment were significantly less than yields from P-treated plots. Maize grain yields were slightly greater in plots alternated with cowpea, compared to continuous maize. Relative agronomic efficiency (RAE) values of OPR and CS were 67% and 75%, respectively, in annual application and 140% and 134% in seasonal applications, respectively, in 2000. In 2001, the trend was almost similar to 2000 except that there was a decline in RAE values of cowpea. Each Naira invested in the annual application returned about ₦3.12 while about ₦2.13 was returned with the seasonal application (₦125.00 is the equivalent of USD$1.00). The OPR and CS can serve as alternatives to water-soluble sources such as SSP.

Rock phosphate enriched post-methanation bio-sludge from kitchen waste based biogas plant as P source for mungbean and its effect on rhizosphere phosphatase activity

Post methanation bio-sludge from a biphasic (aerobic and anaerobic) biogas plant, low grade Indian rock phosphate and two phosphate solubilizing fungi viz., Aspergillus niger TMPS1 and Penicillium oxalicum TMPS3 have been tested for the production of phosphate enriched manure (PEM). A laboratory study revealed that one month incubation was long enough to produce good quality organic P fertilizers having higher water soluble P, lower C:P ratio, higher population of phosphate solubilizing microorganisms and higher phosphatase activity in comparison to biogas sludge. The relative agronomic efficiency of these products was evaluated under greenhouse conditions for mungbean using a 32P radiotracer technique. Relative agronomic efficiencies of phosphate enriched manures inoculated with phosphate solubilizing fungi were better than un-inoculated phosphate enriched manure and equal to single super phosphate (SSP). A significant increase in the population of rhizosphere phosphate solubilizing microorganisms and phosphatase activity was observed in phosphate enriched manure treatments.

RESIDUAL EFFECTS OF PHOSPHORUS SOURCES IN GRAIN AMARANTH PRODUCTION

Productivity of grain amaranth can be improved at a reduced cost through combined use of low-cost rock phosphate (RP) phosphorus sources as well as selection of amaranth varieties with high phosphorus (P) use efficiencies. Rock phosphate sources are known to exhibit differences with respect to grain yield, disease tolerance and P use efficiency (PUE) in amaranth varieties. However, very little is known about their residual release of P. It is probable that the differential performances exhibited by the RPs might be a function of their P residual properties after cropping. Based on these premises this study was carried out to evaluate the residual effects of P sources under continuous croppings for grain amaranth production. The study was a factorial experiment with four replications. Four P sources: single super phosphate – SSP, ogun rock phosphate – ORP, sokoto rock phosphate – SRP, and control; three amaranth varieties: NH84/493, NH84/445 and NH84/452 were factorially combined with two soil types: Kandiudult and Haplustalf. In order to monitor the residual effects of the P sources the experimental plots were cropped consecutively three times. Results from the study revealed that sandy loam Haplustalf was better than the clayey Kandiudult soil in improving grain amaranth yield under continuous cropping system. Grain yield and relative agronomic efficiency (RAE) decreased with continuous cropping for SSP but increased with continuous cropping for ORP and SRP till second cropping, thereafter there was a decrease. Averaged over the three continuous consecutive croppings, SRP and ORP were 68.9% and 73.5% as effective as SSP in increasing grain yield respectively. It was concluded therefore that ORP and Haplustalf soil are best options for grain amaranth production under continuous cropping system.

Short- and long-term effects of sparingly soluble phosphates on crop production in two contrasting Nigerian Alfisols

The effectiveness of Sokoto and Ogun rock phosphates (RP) as substitutes for the conventional phosphorus (P) fertilizer sources in the production of tomato (Lycopersicon esculentum) and okra (Hibiscus esculentus) were evaluated using single super-phosphate (SSP) as reference. Their residual effects were also investigated using rice (Oryzae sativa) and soybean (Glysine max). The two experiments were 2 × 2 × 4 factorial combinations with completely randomized design (CRD) involving two crops, two soils, three P-fertilizer sources and a control. The treatment combinations were replicated four times to give a total of 64 pots, each containing 5 kg of either a slightly acid (pH 6.3) alfisol (Typic Paleudalf) A, from Abeokuta (rainforest ecological zone) or a medium acid (pH 5.9) alfisol (Oxic Paleustalf) B, from Zaria (southern Guinea savanna zone). The soils represent a wide range of Nigerian soils with medium to low P-availability and cultivated to various food and economic crops. The rock phosphates (particularly SRP) were more efficient than SSP in soil A but had less than 50% relative agronomic efficiency (RAE) in soil B, especially when tomato was the test crop. They also had higher RAE in soil A than in soil B when okra was grown, though the efficiency was not as high as that of the reference fertilizer. In the slightly acid alfisol (A), ORP was less efficient than SRP whereas it had 47.8% RAE compared with 34.9% RAE for SRP in the medium acid soil. In the second cropping, the soil from the rainforest zone still produced greater biomass than soil B while soybean gave more biomass than rice. The results confirmed that, apart from crop species to be grown, organic matter and clay contents as well as pH of soils should be considered for efficient utilization of the sparingly soluble phosphates for both short- and long- term effects in crop production.

Effect of Phosphate Rocks on Spring Barley Shoot Yield and Phosphorus Uptake in a Pot Trial

The effect of five rock phosphates (from Algeria, Florida, North Carolina, Senegal, and Morocco) and hyperphosphate on the shoot yield, phosphorus (P) concentration, and P uptake of spring barley was studied in a pot experiment on acidic sandy soil (Nyírlugos) and acidic clay loam soil (Ragály), with superphosphate as the standard P source. The effect of adding calcium carbonate (CaCO3) in combination with superphosphate (SSP) was also investigated. Averaged over the whole experiment, the shoot yield of barley was almost twice as high (3.69 g pot−1) on the clay loam soil from Ragály, which was rich in colloids, than on the colloid‐poor sandy soil from Nyírlugos (1.90 g pot−1). The P uptake, however, was only 25% higher (13.0 mg P pot−1) on the clay loam soil, averaged over the whole experiment, than on the sandy soil (10.4 mg P pot−1). This could be attributed to the fact that the P concentration of barley at tillering was almost 0.1% higher on average in the rock phosphate treatments and 0.2–0.3% higher in the SSP and SSP + CaCO3 treatments on the acidic sandy soil. On both soils, diverse P effects were observed in response to rates of 0–100–400–1600 mg total phosphorus pentoxide (P2O5) kg−1 of the different rock phosphates, adjusted on the active agent equivalence principle. The differences between the P effects, in terms of both biomass surplus and P uptake, exhibited a close correlation with the differences in the P solubility of the rock phosphates. On both soils the greatest biomass surplus and P uptake were recorded for the Algerian rock phosphate, which had excellent natural solubility. Hyperphosphate and the rock phosphates from Morocco and North Carolina were also efficient, whereas the other extreme was represented by the rock phosphates from Senegal and Florida, which had low specific surfaces, P solubility, and lime content. The differences between the rock phosphates could also be expressed in terms of relative agronomic efficiency (RAE %), when the effect of the rock phosphate was compared to that of water‐soluble P fertilizer, in the case of SSP. Averaged over the two soils and over the RAE% calculated on the basis of shoot yield or P uptake, the order obtained for the relative agronomic efficiency of the rock phosphates was the same as that observed for the solubility of the rock phosphates in neutral ammonium citrate. On both soils, the loosest correlation between rock phosphate solubility and either the shoot yield of spring barley at tillering or the P uptake was obtained when the P rates were calculated on the basis of total P content, and the closest correlation was obtained when they were calculated on the basis of the P fraction soluble in neutral ammonium citrate. This, together with the ranking of the rock phosphates on the basis of relative agronomic efficiency, suggests that under conditions similar to those of the present experiment, neutral ammonium citrate is the best solvent for determining the relative P solubility of the rock phosphates. When the effects of the various rock phosphates on the P uptake of spring barley were investigated, a close correlation was detected on both soils between differences in P effects and differences in various properties of the rock phosphates (P solubility, specific surface, CaCO3 content).

Efficiency of indigenous ground phosphate rocks, organic fertilizer and their mixtures for maize performance in two Nigerian alfisols

Greenhouse experiments were conducted to evaluate main and residual effects of sole and combined applications of ground rock phosphates (GRP) and organic fertilizer, (OF) on maize performance in two Nigerian alfisols. A commercial OF (1.33% P 2 O 5 ), Ogun RP (31.00% P 2 O 5 ), Sokoto RP (36.10% P 5 O 2 ) and mixtures of OF with either ORP or SRP were used as “test” fertilizers while single super phosphate (SSP) was the “standard” P fertilizer. There were 7 fertilizer sources (OF, ORP, SRP, SSP, OF+ORP, OF+SRP and OF+SSP), each applied at 2 levels (25 and 50mg P 2 O 5 kg -1 ). The 14 treatments and the control were replicated 3 times in each of 2 soil types (a medium acid Oxic paleustalf, A, from Zaria and another low acid Typic paleustalf, B, from Ibadan), to give a total of 90 experimental pots arranged in completely randomised design (CRD). In the first cropping, the weakly acid soil, B produced taller maize plants (62.3cm) than the medium acid soil, A (60.3cm) after six weeks of growth. However, plants treated to 50mg P 2 O 5 kg -1 of OM+SRP were the tallest (66.3 cm) while the untreated ones were the shortest (55.1cm). In the second cropping, differences in height between plants given the various fertilizer treatments were recorded as early as the 3rd week of growth but there was no difference due to soil type even after five weeks. There was no difference in forage yield that could be attributed to the various fertilizer treatments in the first cropping. During the 2nd cropping, however, SRP, ORP and OF+ORP (at 25mg P 2 O 5 kg -1 ) as well as OF (at 50mg P 2 O 5 kg -1 ) treatments produced higher yields than the control. However, highest P uptake (about 23.5mg pot -1 ) was recorded by plants grown under the influence of OF and SSP fertilizer mixture, irrespective of the soil type. The lowest Relative Agronomic Efficiency (RAE) values estimated for the test fertilizer materials in the 1st cropping were 81.5 and 117.5% in soils A and B, respectively. The respective values for 2nd cropping were 78.3 and 62.0%. It was clear that the indigenous GRP, OF and their mixtures have great potentials as substitutes for the imported soluble P fertiliser sources in the medium and weakly acid alfisols. Key Words: Phosphate rocks; organic fertilizer; maize; Nigerian alfisols Moor J. Agric. Res. Vol.4(1) 2003: 1-7

Eficiência de dois fosfatos naturais farelados em função do tamanho da partícula

Este trabalho foi realizado com objetivo de relacionar o tamanho da partícula de dois fosfatos naturais com seu índice de eficiência agronômica (IEA) para fósforo acumulado em plantas de milho, em dois cultivos sucessivos, sem revolvimento do solo, em casa de vegetação, num LATOSSOLO VERMELHO Distrófico típico corrigido para pH 5,5. As fontes de fosfatos naturais utilizadas foram o fosfato de Gafsa e o fosfato de Gantour Black, com os seguintes tamanhos de partículas: a) < 0,074mm, b) de 0,074 a 0,149mm, c) de 0,149 a 0,297mm, d) de 0,297 a 0,71mm, e) de 0,71 a 1,41mm, f) >1,41mm e g) farelados, em que mais de 80% das partículas tinham tamanho entre 0,074 e 0,5mm. O superfosfato triplo, com grânulos entre 2 e 4mm, foi utilizado como fonte padrão comparativa de fósforo. No primeiro cultivo, os fosfatos naturais finamente moídos (<0,074mm) apresentaram maior IEA; à medida que aumentou o tamanho das partículas diminuiu o IEA dos fosfatos naturais, entretanto, partículas com tamanho até 0,297mm foram reativas. No segundo cultivo, o IEA para partículas com tamanho entre 0,149 e 0,71mm, aumentou e o IEA dos fosfatos naturais farelados foi pouco reduzido em relação aos finamente moídos (<0,074mm). Partículas maiores do que 0,71mm não reagiram durante os dois cultivos. Os fosfatos naturais na forma física farelada mantiveram IEA próximo a 40% nos dois cultivos do milho. O fosfato natural de Gafsa foi mais eficiente do que o fosfato de Gantour Black no suprimento de fósforo no crescimento inicial de plântulas de milho.

Effect of water soluble and water inso luble types of phosphate fertilizer on the growth of coffee seedlings.

A greenhouse study was carried out to evaluate the effects of different sources of phosphorus applied at different rates on coffee (Coffee canephora) seedlings at the headquarters of Cocoa Research Institute of Nigeria, Ibadan in 1999 and 2000. This is towards finding a lasting solution to the problem of P-limitation in soil and supply by the coffee growing farmers. Two sources of phosphorus fertilizers: Single super-phosphate (SSP)(water soluble) and Sokoto rock phosphate (SRP) (water insoluble) were applied at rates equivalent to 20 and 40 kg P205 ha-1. Coffee seedlings with SSP applied at 40 kg P205ha-1 was significantly higher (p< 0.05) in height, leaf area and dry matter yield compared to other application rates. The relative agronomic efficiency of SRP applied at 20kg P205ha-1 was significantly higher (p

Efficiency of sokoto rock phosphate as a fertilizer source for maize production in Southwestern Nigeria

The study on agronomic efficiency of Sokoto Rock Phosphate (SRP) and water Soluble Single Super Phosphate (SSP) as a phosphorus (P) fertilizer sources for maize (Zea mays L. Van TZSRY) was carried out on Iwo Soil Series (Oxic Tropudalf) in the field. The initial (1989) and residual (1990) effects of the two sources of P were assessed. The treatment consist of the control. Two P sources applied at the rates of 25, 50, 100, and 200 kg ha‐1 and their mixtures in equal ratios at the rates of 50 and 100 P ha‐1. The available P was slowly released from SRP in the first year of trial. In the second year however, the SRP supplied significantly higher P than the SSP. The effectiveness of the different rates of SRP in increasing maize grain yields in the initial experiment followed the order of SRP25 > SRP50 > SRP100 > SRP200 while the residual effect after one year on yield was as follows: SRP50 > SRP100 = SRP200 > SRP25. The optimum grain yields of 5.9 and 5.1 tonnes ha‐1 were obtained with SSP at the rate of 50 and 100kg ha‐1 in the initial (1989) and residual (1990), respectively. The optimum grain yield could not be ascertained in the initial (1989) experiment for SRP because the yield declined as the rates of SRP increased. But in the residual (1990) effects, it was 4.9 tonnes ha‐1 at the rate of 50kg ha‐1. The relative agronomic efficiency values ranged from ‐500% to 0% and 150% to 100% in the initial and residual effects, respectively. This indicates that Sokoto Rock Phosphate was more effective in supplying P for maize growth in the second than the first year of the experiment.

Greenhouse evaluation of phosphate fertilizers produced from Togo phosphate rock

Abstract Partial acidulation of phosphate rock (PR) or compaction of PR with soluble P fertilizers represents a means of producing P fertilizers from indigenous PR sources that may otherwise be unsuited for use as a P fertilizer. In the present two greenhouse experiments, we compared the agronomic effectiveness using a relative agronomic efficiency (RAE) index for the following P fertilizer sources: (i) ground Togo PR; (ii) partially acidulated phosphate rock (PAPR) at 50% acidulation with H2SO4; (iii) PR compacted with triple superphosphate (TSP), urea, and KCl at P ratio of PR: TSP = 50: 50; and (iv) commercial‐grade single superphosphate (SSP). The soil used was an acid Bladen sandy loam (Typic Albaquult) limed to pH 5.5 prior to cropping with maize for 6 weeks or cowpeas grown to maturity. Rates of P applied were 0, 50, 100, 150, and 200 mg P/kg. All treatments received adequate rates of N and K, as well as secondary and micronutrients. The results showed that ground Togo PR was an ineffective P sourc...

Crop Recovery and Nitrification of Fall and Spring Applied Anhydrous Ammonia1

AbstractTo evaluate the relative agronomic efficiency of and potential NO3, pollution by fall and spring applied anhydrous NH3, N uptake and yield response by corn, and detailed sampling of the NH3, bands were conducted. Nitrogen significantly increased grain yield and N uptake by corn (Zea mays L.) on a Plano sil (0.216% N) and a Pella loam (0.447% N) in south central Wisconsin. There were no differences between fall and spring application of N. Crop recovery of applied N depended on soil type and rate of application, and at most amounted to 40% of the N applied. Depending on rate of application, from 68 to 86% of the fall‐applied NH3, was nitrified before mid‐May. Nitrite accumulated within both fall and spring applied bands, the highest concentrations being detected in early spring within fall applied bands. Persistence of NO2 was more prolonged on a neutral than on a slightly acid soil. Accumulation of NO2 must be considered undesirable because of possible phytotoxicity and losses through biological or chemical denitrification, and fall application appears to offer a great potential for these processes to occur.