Judicious Use Of Fertilizers Research Articles

The Potential of Soil Carbon Sequestration Through Improved Management Practices in Norway

The study was conducted to assess the potential of Norwegian agricultural ecosystems to sequester carbon (C) based on the data from some long-term agronomic and land use experiments. The total emission of CO2 in Norway in 1998 was 41.4 million metric ton (MMT), of which agriculture contributed only 0.157 MMT, or <0.4% of the total emissions. With regards to methane (CH4) and nitrous oxide (N2O) gases, however, agricultural activities contributed 32.5% and 51.3% of their respective emissions in Norway. The soil organic carbon (SOC) losses associated with accelerated soil erosion in Norway are estimated at 0.475 MMTC yr−1. Land use changes and soil/crop management practices with potential for SOC sequestration include conservation tillage methods, judicious use of fertilizers and manures, use of crop residues, diverse crop rotations, and erosion control measures. The potential for SOC sequestration is 0.146 MMTC yr−1 for adopting conservation tillage, 0.011–0.035 MMTC yr−1 for crop residue management, 0.026 MMTC yr−1 for judicious use of mineral fertilizer, 0.016–0.135 MMTC yr−1 for manure application, and 0.036 MMTC yr−1 for adopting crop rotations. The overall potential of these practices for SOC sequestration ranges from 0.591 to 1.022 MMTC yr−1 with an average value of 0.806 MMTC yr−1. Of the total potential, 59% is due to adoption of erosion control measures, 5.8% to restoration of peat lands, 21% to conversion to conservation tillage and residue management, and 14% to adoption of improved cropping systems. Enhancing SOC sequestration and improving soil quality, through adoption of judicious land use and improved system of soil and crop management, are prudent strategies for sustainable management of soil, water and environment resources.

Sustainability of fallow - Indian mustard (Brassica juncea) system as influenced by green manure, mustard straw cycling and fertilizer application

A field experiment was conducted for five consecutive years (2005-06 to 2009-10) to evaluate the effect of dhaincha ( Sesbania aculeata) green-manuring (GM), mustard [ Brassica juncea (L.) Czern &amp; Coss] straw cycling and fertilizers on productivity and sustainability of mustard under fallowmustard sequence. Sesbania (GM) and mustard straw cycling significantly influenced plant height, branches/plant, siliquae/plant, seeds/siliqua as well as seed and oil yields compared to existing fallow-mustard practice. The pooled mustard seed yield registered 42.3% increase due to Sesbania (GM) alone and 63.9% due to green manuring + mustard straw cycling. Increase in fer- tilizer levels from 40 kg N to 80 kg N and 8.7 kg P to 17.4 kg P significantly improved mustard yield attributes and seed and oil yields, while results of K application were inconsistent. The combined application of 80 N + 17.4 P + 33.3 K kg/ha synergistically increased the seed yield by 82.1% over 40 N + 8.7 P kg/ha. Supplementary use of balanced fertilizers (80 kg N: 17.4 kg P: 33.3 kg K) to either of organic treatments, synergistically improved the seed yield at least by three-fourth times. Sustainability yield index, partial factor productivity, production efficiency and incremental benefit cost ratio also showed significant improvement due to Sesbania (GM), mustard-straw cy- cling and judicious fertilizer use.

Phosphorus management in continuous wheat and wheat-legume rotations

The sustainability of cropping systems is closely related to the judicious use of fertilizers. Little research has been conducted on the management of P in rotations in Morocco. The purpose of this study was to determine the effects of direct, cumulative, and residual P on wheat (Triticum aestivum) and chickpea (Cicer arietinum L.) yields under field conditions in two cropping systems: continuous wheat (W-W) and chickpea-wheat (CP-W). Experiments were conducted in 1994–96 at two locations in the arid and semiarid regions of Morocco. Phosphorus was applied the first year at rates of 0, 9, 18, and 27 kg P ha−1 on both wheat and chickpea. The second year, plots were split into treatments with P and without P fertilizer. The changes in NaHCO3-P in soil showed that after two years of cropping, P rates of 9 and 18 kg P ha−1 were needed to increase and maintain soil test P level in the range where a third successive crop could be grown without fertilization at locations 1 and 2, respectively. Also, soils with the same initial NaHCO3-P soil test levels required different amounts of fertilizer P to produce maximum yields. Inclusion of chickpea in the rotation resulted in a greater response to residual P by wheat at location 2. Differences in wheat grain yield between rotations were not significant. The maximum increase in yields above the nil-P treatment due to the highest amount applied in the the previous year was 1.3 t ha−1, obtained for continuous wheat at location 2. Though the residual P effect was evident in this study, it did not produce maximum yields. Yields (GY, DM) could be predicted by the inclusion of both P applied in previous year (PR) and P applied in the current year (CP) by the following model: GY or DM = a + b*Ln(RP+1) + c*Ln(CP+1). Based on the range of P rates used in this study, a single P application for a 2-year rotation is not a suitable practice in these soils. The application of 18 kg P ha−1 each year is recommended for continuous wheat, and 9 kg P ha−1 the first year plus 18 kg P ha−1 the second year is recommended for chickpea-wheat rotations. We suggest that either using single large applications of P or performing repeated applications should take into account the range of targeted application rates.

Assessment of soil and plant analysis laboratories in the West Asia‐North Africa Region

Although limited amount of water is the primary constraint to agricultural productivity in the rainfed area of West Asia and North Africa (WANA), yields are also low because of the poor mineral nutrient status of soils. Yields can, therefore, be considerably increased by judicious fertilizer use. Laboratories for soil and plant analysis are essential for identifying nutrient constraints and providing a basis for efficient fertilizer use, through correlation studies to establish suitable soil testing extractants and calibration studies with crop responses. The Soils Laboratory at the International Center for Agricultural Research in the Dry Areas (ICARDA) has initiated a quality control program among the national agricultural research systems (NARS) in the countries of the WANA region. The efforts include linkages with the Wageningen International Soil Analytical Exchange Program, in‐country training courses, and a laboratory analysis manual. Continued improvement in laboratory performance is dependent upon knowledge of the capabilities of such laboratories and identification of their constraints. This presentation reports a fact‐finding survey of laboratories from 16 countries of the WANA region—mainly public, from universities and ministries of agriculture, and some private or commercial ones—based on a questionnaire about analyses, facilities, methodologies, quality assurance, personnel training, and management. Future efforts to improve the quantity and quality output from of these laboratories will address such deficiencies.

Chemicals Used in Southern Forest Nurseries

Abstract Large-scale tree planting programs have placed a tremendous pressure on nursery managers to supply unprecedented numbers of seedlings. Inclusion of chemicals into seed production regimes have made it possible for southern pine nurseries to be the most productive in the world, in terms of both output per nursery and average cost per seedling. Nursery managers in the South rely on the use of fertilizers, fumigants, and pesticides to help keep production costs low. Judicious use of fertilizers can reduce the production of cull seedlings as well as increase field growth after outplanting. It has been our experience that investing in the use of pesticides and inorganic fertilizers provides a high rate of return for the nursery manager. South. J. Appl. For. 20(3):127-135.

New diagnostic tools for tissue testing

Abstract Diagnostic procedures that identify nutrient deficiencies and excesses in crops will likely gain prominence in the future. One reason is environmental concerns are driving producers to more timely and judicious use of fertilizers and waste products. Economics is an equally important factor that ultimately dictates producer practices. Advancements made in global positioning systems (GPS), geographical information systems (GIS), and variable rate application technology (VRAT) have made it possible to make nutrient management practices more site specific and reduce losses through runoff and leaching. These technologies open many opportunities for tissue testing because as whole‐field fertilizer application practices become more closely scrutinized, and nutrient deficiencies will become more obvious. Diagnosing these deficiencies will likely involve a combination of new technologies, such as on‐the‐go yield monitoring devices and aerial photography to identify problem areas in fields. Various analyti...

Overcoming soil nutrient constraints to crop production in West Africa: Importance of fertilizers and priorities in soil fertility research

The Alfisols, Oxisols, Ultisols and Inceptisols which dominate the soils of West Africa have sustained crop growth for a very long time. As a consequence, their fertility has become perilously low and the task of increasing or even maintaining the productive capacity of these soils has become perhaps the greatest challenge to agricultural scientists in this latter half of the 20th century. Water is useful not only for the growth of plants but also for the efficient use of costly inputs such as fertilizers. On the other hand, fertilizers increase the water-use efficiency. Such interactions must be closely studied so as to maximize the impact of inputs of agricultural production. The nutrients in the soil are always in a state of flux, with additions and subtractions. Monitoring the dynamics of the nutrients would promote their efficient use by crops and prolong the productive life of the soils. Several models currently exist for the study of organic matter dynamics in soils. These models should be applied to the West African situation since it is vital to develop management practices that can promote efficient use of nutrients released during mineralisation of soil organic matter. Judicious fertilizer use in West Africa should be promoted as this practice will enhance agricultural production while protecting the fragile environment.

Long-term effect of cassava cultivation on soil productivity

Cassava ( Manihot esculenta Crantz) is usually grown by poor farmers in the tropics with a minimum of inputs. Continuous production under these conditions can lead to soil nutrient depletion. On sloping land, cassava cultivation can also cause severe erosion if the crop is not properly managed. This paper reviews the literature to show that cassava does extract large amounts of nutrients, especially potassium (K), from the soil. However, when nutrient extraction is calculated on the basis of per unit quantity dry-matter produced, cassava extracts much less N and P than, and similar amounts of K to, most other crops. Long-term fertility trials indicate that, without adequate K fertilization, cassava yields eventually decline due to K depletion, except in those soils containing large amounts of K-bearing minerals. While cassava production may result in severe erosion when grown on steep slopes, simple agronomic practices can usually maintain soil losses within acceptable levels. The effect different cultivation practices on erosion and yield varies from location to location, and the most appropriate practices can be identified through simple erosion-control trials on farmers' fields. Thus, productivity of continuously grown cassava fields can be maintained through judicious use of fertilizers and soil management practices that control erosion.

Effect of long-term fertilizer treatments on groundnut yield, nodulation, and nutrient uptake at Samaru, Nigeria

It was observed in a long-term fertility study that P application results in better nodulation and seed yield. The N yield per plant increased significantly with P, K, and B application, but the promoting effect of K and B on N content per plant was not reflected in the final yield. Data on mean nutrient uptake indicate that about 63% of N, 68% of P, 23% of K, 4% of Ca and 24% of Mg were present in the kernels, the remainder being in the haulm and shells. Soil will be exhausted fast if the nutrient rich groundnut residues are completely exported from the field and not compensated by adequate fertilizer application. Judicious use of fertilizers on groundnut has been shown to yield more than 100 kg of biologically fixed N per hectare.

Yield Response of a Tall Fescue‐White Clover Sward to Fertilization With Nitrogen, Phosphorus, and Potassium

AbstractThe effects of different amounts of nitrogen, phosphorus, and potassium on productivity of a sward of ‘Kentucky 31’ tall rescue, Festuca arundinacea Schreb., and Ladino white clover, Trifolium repens L., were observed over a 4‐year period. The plant association was established by seeding on a low‐phosphorus Tilsit soil. Yields were obtained by clipping 5 to 7 times annually.Spring‐applied nitrogen at rates up to 270 kg per hectare (240 pounds per acre) did not increase total annual herbage production but resulted in larger yields during spring and early summer with proportionately less growth in late summer and autumn. Split applications of 135 or 270 kg of nitrogen per hectare annually improved herbage production to the extent of approximately 6 kg dry herbage per kg of applied nitrogen.Phosphorus additions markedly increased herbage growth, an annual application of 9.8 kg per hectare resulting in approximateley 1125 kg more dry matter per hectare. The application of potassium did not affect production initially, but a small yield response was observed the last year. Interactions between elements were relatively unimportant.The findings indicate the importance of judicious use of fertilizer, especially on soils of low crop‐yield potential, if livestock products are to be produced efficiently from grasslands.