High P-fixing Capacity Research Articles

Fertility Assessment of a Farm Soil (Ferrosol) Located in Toowoomba, Queensland

A series of analyses and bio-essays were conducted on a Ferrosol collected in Toowoomba (Queensland) to assess its nutrient status and suitability for cereal cropping. The aim was to reveal its nutrient deficiencies or sufficiency and make sound fertilizer recommendations for cereal cropping. An omission trial was first run followed by Phosphorus rate and adsorption trials. Omission and rate trials were conducted on pots with maize as a test plant. Besides, soil chemical analyses were carried out. Results of these analyses revealed that the soil was deficient in key micro- and macro-nutrients and that it exhibited a high P-fixing capacity. This latter property is manageable with addition of organic amendments. The following report presents and discusses these results.

Effects of phosphorus-based application of animal manure compost on the yield of silage corn and on soil phosphorus accumulation in an upland Andosol in Japan

Animal manure contains significant amounts of nitrogen (N) and phosphorus (P) that can be utilized as fertilizer. However, manure application rates are generally set to meet crop N demand, which results in excess P application which increases the risk of P loss into bodies of water. We examined the application method of manure compost based on crop P demand on the dry matter yield of silage corn (Zea mays L. var. indentata), on nutrient uptake and on soil P accumulation in an upland Andosol with a high P-fixing capacity. Cattle and poultry manure composts (CMC and PMC) with different P solubility were applied to meet the crop’s N requirements (N-based application) or P requirements (P-based application) in 3 consecutive years. Supplemental N was applied using polyolefin-coated urea in the P-based treatments. The dry matter yields and nutrient uptakes of silage corn in the P-based CMC and PMC application systems were similar to those in the corresponding N-based systems. The average relative efficiency of N in CMC (33%) was close to the predicted value (30%) during the study. On the other hand, the relative efficiency of N in PMC (42%) was higher than the predicted value (28%). The average relative efficiency of P from CMC and PMC was 109% and 50%, respectively. These were higher than the predicted values based on the available P proportion (the sum of water- and sodium bicarbonate-soluble P) for CMC (78%) and PMC (34%), indicating that the available P fraction in the manure composts was more effective than that in P fertilizer for corn growth or that the other P fractions were also effective for corn. P-based manure compost application lowered the soil P accumulation to between 41 and 43% of the value in the N-based accumulation (versus a value of between 31 and 40% of that value for soil Truog-P). Compared to N-based manure compost application, P-based manure compost application with supplemental N fertilizer produced similar dry matter yields of corn and suppressed soil P accumulation in the upland Andosol field.

Phosphorus fixing capacity of the Oxic Rhodustalf—alfisol soil in the Chotanagpur plateau region of Eastern India

The P-fixing capacity of a soil governs the P-nutrition of crop plants. P-nutrition of the crop plant is more a soil problem and a higher dose of phosphatic fertilizer is necessary for soils having high P-fixing capacity. The phenomenon of P-fixation and the great variation in the P-fixing capacity of different soils has thus important bearing on crop response to P-application. The eastern plateau region of India with acid lateritic soil is chronically deficient in available phosphorus resulting in very low productivity. An experiment was thus carried out to estimate the P-fixing capacity of soil collected from two depths, 0 - 20 cm and 20 - 50 cm, from the Agricultural experimental farm of Indian Statistical Institute, situated at Giridih, Jharkhand, in the eastern India. The soil was acidic in reaction (pH-5.4) with presence of Fe (1.60%) and Al (17.2%). The P-fixing capacity of the soil was estimated to be 59.60% and 64.94% for the surface and the subsurface soil respectively showing lower P-fixing capacity of the surface soil as compared to the subsurface soil which may be due to presence of more organic matter in the surface soil as organic molecules released on decomposition of organic matter complexes with Fe and Al in the soil thereby blocking the P-fixing sites in the soil.

Using agroforestry to improve soil fertility: effects of intercropping on Ilex paraguariensis (yerba mate) plantations with Araucaria angustifolia

This study assessed the use of agroforestry to improve soil nutrient properties in plantations containing Ilex paraguariensis St. Hilaire (yerba mate). Intercropping within tree plantation systems is widely practiced by farmers around the World, but the influence of different species combinations on system performance still requires further investigation. I. paraguariensis is a major South American crop commonly cultivated in intensive monocultures on low activity clay soils, which are highly prone to nutrient deficiencies. Study plots were established in 20 plantations in Misiones, Argentina. These involved two species combinations (I. paraguariensis monoculture and I. paraguariensis intercropped with the native tree species Araucaria angustifolia) and two age classes (30 and 50 years old). Chemical soil samples were analysed to determine Ca, Mg, K, P, N, C and Al concentrations, effective CEC (eCEC) and pH at two soil depths (0–5 cm and 5–10 cm). In the younger plantations, the agroforestry sites had lower nutrient levels than I. paraguariensis monoculture sites. However, the monoculture plantations were more susceptible than agroforestry sites to a decline in soil nutrient status over time, particularly with respect to Ca, eCEC, N and C for both soil depths. P concentrations were below detection limits for all sites, potentially reflecting the high P-fixing capacity of the kaolinic soils of this region. While agroforestry systems may be better at maintaining soil quality over time, significant growth increase of I. paraguariensis was apparent only for the monoculture sites.

DIVERSITY OF ARBUSCULAR MYCORRHIZAL FUNGI IN HORTICULTURAL PRODUCTION SYSTEMS OF SOUTHERN CHILE

ABSTRACT The diversity of arbuscular mycorrhizal (AM) fungi in six Capsicum annuum or Lycopersicum esculentum L. horticultural production systems of small farmers, and of two wheat agrosystems was comparatively investigated in Southern Chile (La Araucania). Soils in this region are mostly originated by volcanic ashes which are characterized by high organic matter content and high P-fixing capacity. Arbuscular mycorrhizal fungal symbioses are playing a key role for P uptake by horticultural crops grown there. The objective of this study was to determine AM fungal communities in cropping systems and to identify soil factors affecting their frequency and diversity. Of the totally 32 AM fungal species identified, 5 to 21 AM fungi species were found in horticultural locations and 8 to 11 AM fungi species in conventional tillage (CT) and no-tillage (NT) agroecosystems. No relationships on AM fungal diversity with soil factors were found. In wheat based agrosystems fungal diversity was somewhat lower under CT than NT whereas no such relationships between diversity and intensity of land use could be generated from horticultural systems. It is concluded that it will be advisable for farmers to inoculate their horticultural crops with selected mycorrhizal inoculants during the nursery stage, as it cannot be predicted from the soil conditions whether the native AM fungal community is sufficient to sustain a stable horticultural production in the region.

Fifty Years of Fertilization Experiments on Pinus pinaster in Southwest France: The Importance of Phosphorus as a Fertilizer

Abstract Data from 50 years of fertilization trials on Maritime pine (Pinus pinaster) were compiled to investigate how growth was affected by fertilization or improved nutrient availability. The results demonstrated that only trees fertilized with phosphorus (P) fertilizers showed an overall improvement in productivity. The effects were significant mainly at wetter sites and were less effective at drier sites. The form of P fertilizer does not seem to be important, and a rate of about 17–35 kg of P ha−1 applied as a single dose at stand establishment was found to be sufficient to obtain a significant improvement in growth. Foresters can expect an increase of 20–40% cumulative volume at rotation age or a reduction of 4–5 years in rotation length due to fertilization with P. The duration of the effect of P fertilization on the annual increment varied (up to 20 years after application in the best cases). The high P-fixing capacity of these soils appears to be the most important factor in explaining differential responsiveness to P fertilizers, but stand developmental stage or the appearance of other limitations such as nitrogen may also explain the decline in the effectiveness of P fertilization with age.

Effect of arbuscular mycorrhizal fungi and phosphorus fertilization on the post vitro growth and yield of micropropagated strawberry grown in a sandy loam soil

Strawberries (Fragaria ×ananassa Duch.) grown in alfisols of semiarid areas in India results in suboptimal yields. Low organic carbon and low phosphorus (P) availability, in addition to high P fixation, affects P availability drastically, even when it is applied externally. The benefit to the yield of micropropagated strawberry Fragaria ×ana nassa 'Pajaro' through inoculation with arbuscular mycorrhizal (AM) fungi and P application was examined in a field experiment. AM response was evaluated at four doses of P (50, 100, 150, and 200 kg P·ha–1) in a high P-fixing capacity and P-deficient alfisol. At harvest, all inoculated plants, except those at the highest level of applied P (200 kg·ha–1), had larger fruit yields per plant, unit mass, number of runners, higher shoot dry matter, and shoot P content. However, the AM response as measured by yield varied with P concentration. Inoculated plants had a significantly greater fruit yield when grown at 150 kg P·ha–1, and the yield was comparable with uninoculated plants grown at 200 kg P·ha–1. The external P requirements were 71 kg·ha–1 for mycorrhizal and 106 kg·ha–1 for nonmycorrhizal strawberry plants to obtain 90% of the maximum fruit yield. In terms of P fertilization, this corresponds to a savings of 35 kg·ha–1. The percent mycorrhizal root length colonization, both in inoculated and noninoculated plants, was not found to differ significantly with P application.Key words: strawberry, P fertilization, mycorrhizal dependency.

Phosphorus exchangeability and leaching losses from two grassland soils.

Although phosphate phosphorus (P) is strongly sorbed in many soils, it may be quickly transported through the soil by preferential flow. Under flood irrigation, preferential flow is especially pronounced and associated solute losses may be important. Phosphorus losses induced by flood irrigation were investigated in a lysimeter study. Detailed soil chemical analyses revealed that P was very mobile in the topsoil, but the higher P-fixing capacity of the subsoil appeared to restrict P mobility. Application of a dye tracer enabled preferential flow pathways to be identified. Soil sampling according to dye staining patterns revealed that exchangeable P was significantly greater in preferential flow areas as compared with the unstained soil matrix. This could be partly attributed to the accumulation of organic carbon and P, together with enhanced leaching of Al- and Fe-oxides in the preferential flow areas, which resulted in reduced P sorption. The irrigation water caused a rapid hydrologic response by displacement of resident water from the subsoil. Despite the occurrence of preferential flow, most of the outflowing water was resident soil water and very low in P. In these soils the occurrence of preferential flow per se is not sufficient to cause large P losses even if the topsoil is rich in P. It appears that the P was retained in lower parts of the soil profile characterized by a very high P-fixing capacity. This study demonstrates the risks associated with assessing potential P losses on the basis of P mobility in the topsoil alone.

Compositional Nutrient Diagnosis of the P Status in Potato Crops

In Quebec, potato crops are largely grown on light acid soils altered by podzolization. In the plow layer, abundance of sesquioxides, low pH and low organic matter content produce high P-fixing capacity. Liming to pH not exceeding 5.6, organic matter additions and banding of P fertilizers are practices to improve the P status in the soil–plant system. Plant response to treatments could be diagnosed by yield evaluation and foliar analysis. Agricultural lime, dolomitic limestone and basalt were applied to an acid soil (pH 4.6). Ordinary superphosphate, biosuperphosphate, triple superphosphate, and diammonium phosphate impregnated with humic peat were banded at two rates. Highest tuber yield was 40 t·ha–1. There was no response to liming materials as pH did not exceed 4.9. There was a significant response to P fertilizers. Nutrient balance assessment of the foliage by Compositional Nutrient Diagnosis indicated a critical “d” value of 1.5 and a critical P index of 0.8.

Título en español.

Dos cosechas consecutivas de plátano se recolectaron en un experimento sembrado en un suelo Ultisol que tiene una alta capacidad para la fijación del P. El estudio se diseñó para evaluar el comportamiento del plátano a varios niveles de N aplicados en franjas y al voleo, y además, para medir el efecto de aplicaciones de P al momento de sembrar, así como el efecto residual de aplicaciones anteriores. En las plantas que no recibieron aplicaciones de N se observaron carencias de N y Mg. Estas se verificaron por análisis de tejidos de las hojas. Los datos de rendimiento de la plantilla pueden resumirse como sigue: el peso de los racimos y el número y peso de las frutas de tercer gajo fue significativamente mayor en las plantas que recibieron N en franjas a razón de 224 kg./ha. que en las que no lo recibieron. No hubo diferencias en cuanto al número de frutas por racimo que puedan atribuirse a la aplicación de N en franjas o al voleo aún a los mismos niveles. El peso del racimo y de la fruta aumentaron cuando se incrementó la aplicación de P de 0 a 56 kg./ha. al momento de sembrar y con 179 kg./ha. de P residual (aplicado en 1970). La falta de P disminuyó el peso y el contenido de pulpa de las frutas en el tercer gajo. Los datos de la segunda cosecha, el retoño, revelan que las aplicaciones de N no afectaron el peso del racimo y que no se registraron respuestas a aplicaciones de P. La producción de la cosecha de retoño fue solamente 13% menor que la de la plantilla. En general, los datos indican que cuando se usan cultivares de alto potencia productivo, se usan siembras más densas, se siguen prácticas adecuadas de control de plagas y otras prácticas mejoradas de cultivo, incluyendo el abonamiento racional, es posible obtener altos niveles de producción en los suelos ácidos y de baja fertilidad inherente como lo son los Ultisols. De ambas cosechas, plantilla y retoño, se obtuvieron más de 300,000 frutas/ha.