NPK Supply Research Articles

Exploring the Effect of Humic Acid on Chlorophyll Levels in Japanese Mint under Drip and Flood Irrigation Amidst Water and Nutrient Constraints

A field experiment on Mentha (Mentha arvensis L.) was conducted during the spring seasons of 2022 and 2023 at G.B. Pant University of Agriculture and Technology, Pantnagar. The objective was to investigate the impact of foliar spray of humic acid on SPAD values under conditions of limited water and nutrients. The experiment comprised two drip irrigation levels (80% and 100% of crop evapotranspiration) and four nutrient management practices. These practices included: 25% NPK basal + 75% NPK fertigation, 50% NPK basal + 50% NPK fertigation, No basal + 75% NPK fertigation + three foliar sprays of humic acid at 0.3%, and 25% NPK basal + 50% NPK fertigation + three foliar sprays of humic acid at 0.3%. The experiment was laid out in a randomized block design with three replicates (factorial), and an extra control was included. The control followed conventional practices, where the crop received recommended doses of fertilizers (N: P2O5: K2O @ 120:60:40 kg/ha) and was irrigated at an IW: CPE ratio of 1.2 with a 5 cm irrigation depth. Significantly higher SPAD values were observed when the crop was irrigated at 100% ETc level of drip irrigation and with nutrient management practices involving foliar application of humic acid, compared to 80% ETc level of drip irrigation and total NPK supply through chemical fertilizers, respectively. At harvest, crops irrigated at 100% ETc level recorded SPAD readings that were 11.1% and 18% higher than those irrigated at 80% ETc level during 2022 and 2023, respectively. The humic acid application helped to maintain the SPAD values even after a 25% reduction in nutrient dosage. SPAD values for control were significantly lower than the combination of best nutrient management practices with either 80 or 100% ETc level of drip irrigation.

The Application of Nitrogen, Phosphorus, and Potassium Regulate the Growth and Morphological Development of Torreya grandis (Taxaceae) Saplings

Torreya grandis Fort. ex Lindl. cv. “Merrillii” is an important woody oil crop, and the development of plantations relies on the cultivation of high-quality saplings. For this study, 6-year-old grafted T. grandis saplings, which will soon be planted on the mountain, were selected to investigate the regulatory effects of nitrogen (N), phosphorus (P), and potassium (K) on their growth and morphology. To determine the optimal dosage and ratio of N–P–K fertilizer for sapling cultivation, we employed a three-factor four-level L16 (43) orthogonal experiment design. The experiment included a total of 17 treatments—a control group where no fertilizer was applied and 16 treatments with varying levels of NPK supply. We conducted a one-season experiment under a prescribed fertilizer regime and measured root collar diameters and sapling heights, the root, shoot, leaf biomass, total biomass, and the nutritional status of plant organs (root, shoot, leaf). From these measurements, we calculated the root–shoot ratio (RS) and seedling quality index (QI). The application of N–P–K fertilizer exhibited significant benefits for T. grandis sapling cultivation, promoted their growth and biomass accumulation and altered the nutrient allocation patterns in organs. Ultimately, we determined the ideal N–P–K ratio for T. grandis growth to be 1:0.46:0.75, with a fertilizer application of 1.38 g·sapling−1 of N, 0.64 g·sapling−1 of P (P2O5), and 1.04 g·sapling−1 of K (K2O).

Analysis of Critical Facilities of Rice Value Chain Actors in Benue and Nasarawa States Nigeria

The study was carried out to specifically to analyse the critical facilities of rice value chain actors in Benue and Nasarawa States, Nigeria. The population of the study comprised all rice value chain actors in the two states. Structured questionnaire was used to collect data from 320 respondents from the two states. Multi-stage sampling procedure, stratified:-purposive and simple random sampling techniques were used for the study. Descriptive statistics such as frequencies, percentages, mean, standard deviations were used to analyse the data for the study. It was evident from the study that the pooled mean results indicated that producers’ most critical facilities were planters (97.8%), harvesters (97.2%) and threshers (97.2%) in Benue and Nasarawa States respectively. Sources of foundation seeds (98.7%), supply of foundation seeds (98.4%) and NPK: 27:13:13 (96.2%) were the most critical facilities to input suppliers. Electricity need (91.8%), de-stoners (90.2%) were the critical facilities to processors. Marketers’ value chain actors indicated transportation (74.7%) packaging (70.9%) and storage (63.3%) as their critical facilities in the rice value chain respectively. The study concluded that rice value chain actors are affected by the poor availability of critical facilities needed by the value chain actors in Benue and Nasarawa states. It was recommended that critical facilities should be made available by government for easy access by the various rice value chain actors at subsidized rate for their effective utilization and enhanced performance.

Сортова специфіка потреб пшениці озимої в елементах живлення в умовах нестійкого зволоження

Goal. To identify the peculiarities of the accumulation of nutrients in the productive part of plants of new varieties of winter wheat in years with different hydrothermal conditions after the restoration of vegetation. Methods. On typical chornozems of varietal testing grounds after the restoration of spring vegetation in 2018 – 2020, the supply of NPK, Zn, Mn, and Cu to winter wheat plants of 4 varieties of national standards and 8 varieties of selection of EU countries was studied. Results. Among the varieties of foreign selection, the highest nitrogen content in grain for the entire period of research was in the variety Arktis (2.34%), among domestic varieties — Bunchuk (2.18%), the lowest — in the varieties Manditsa (1.62%) and Smuglianka (1.83%). The variety Rozkishna is relatively undemanding to phosphorus and potassium, the variety Bodichek — to potassium, regardless of growing conditions. A variable consumption response was also fixed. Under favorable moisture conditions, the plants of the variety Annitsa increased the accumulation of RK, the variety Arktis — of P. The variety Dariya has a constant high need for Zn and Mn, but a variable need for Cu, while the variety Matrix — a constant low need for Zn and Mn. Recommendations were developed for increasing or decreasing the rates of application of NPK, fertilizers, and microelements for each studied variety of foreign selection concerning the norms of fertilization of national standards. Conclusions. Varieties with signs of constant increased or decreased accumulation of nutrients, as well as varieties that change the concentration of NPK and trace elements in the final product in years with arid and favorable weather conditions of spring vegetation were identified. It is proposed to test the nutrition of new varieties of wheat during variety testing to further adjustment of the rates of fertilizer application.

Zinc and iron biofortification in pearl millet cultivars as influenced by different fertifortification strategies in semi arid tropics

Two field experiments were conducted during Kharif 2018 and 2019 on clay loam soils at Zonal Agricultural and Horticultural Research Station, Babbur farm, Hiriyur, Karnataka to evaluate the performance of pearl millet cultivars by different zinc (Zn) and iron (Fe) fertifortification methods. Micronutrient (Zn and Fe) management strategies were employed in main plots that include application of recommended NPK, along with recommended NPK supply of Fe and Zn through soil, foliar application and FYM enrichment along with plant growth promoting rhizobacteria (PGPR). Three pearl millet cultivars [Variety - ICTP 8203 Fe (Dhanshakti), Hybrid - ICMH 1202 and local cultivar (variety - WCC 75)] were considered in sub plots laid in split plot design with three replications. Three methods of micronutrient application tested improved the grain Fe and Zn concentrations of both biofortified cultivars Dhanshakti and Hybrid along with grain yield. Enrichment of FYM with Fe and Zn resulted in higher concentration and uptake of Fe and Zn than other modes of micronutrient application. The hybrid ICMH 1202 had obtained significantly higher grain yield (2203 kg ha−1), grain micronutrient concentration of pearl millet (50.52 and 83.88 mg kg−1 Zn and Fe, respectively) with the application of enriched FYM + PGPR along with recommended NPK and found the best.

Influence of Integrated Nutrient Management on Yield of Coconut (Cocos Nucifera) on Sandy Soils

The study mainly to find out the effect of activated biomass on the yield of 10 years of Ceylon tall coconut plants at bris soil to develop a fertilizer mixture that supports plant productivity. The activated biomass was derived from coconut fronds and empty fruit bunch which were air-dried and carbonized in a stainless steel fabricated kiln at a temperature between 250oC-350oC for 4 h to develop the activated biomass. Seven treatments including control were selected. Measurements of yield parameters viz., fruit weight, nut weight, husk weight, water volume, fruit perimeter, fruit length, flesh thickness and the number of nuts increased were conducted every 2 months. There are significant differences at (P<0.05) were observed in some yield parameters, percent of nut increased, flesh thickness and fruits parameter were highest at T3. The treatment of T6 shows the highest records of fruits length, water volume, the weight of fruits, and husks weight. T7 recorded the highest reading of stem diameter. Further field evaluations are needed to determine the relationship of the level of activated biomass with the different level amount of NPK supply in inducing the nutrient availability and soil microbial.

Assessment of Composted Pelletized Poultry Litter as an Alternative to Chemical Fertilizers Based on the Environmental Impact of Their Production

Reducing the use of chemical fertilizers in agriculture is one of the EU Green Deal’s priorities. Since poultry production is increasing worldwide, stabilized poultry litter such as composted pelletized poultry litter (CPPL) is an alternative fertilizer option. On the contrary, compared to chemical fertilizers, the environmental impacts of composted products have not been adequately studied, and no data are currently available for CPPL produced by a closed composting system, such as the Hosoya system. The aim of this research was to assess the role of CPPL as a potential alternative for chemical fertilizer by evaluating the environmental impact of CPPL production via the Hosoya system using common chemical fertilizers. Based on life cycle assessment (LCA), the environmental impact (11 impact categories) was determined for the production of 1 kg of fertilizer, as well as for the production of 1 kg of active substances (nitrogen (N), phosphorus pentoxide (P2O5), and potassium chloride (K2O)) and the theoretical nutrient (NPK) supply of a 100 ha field with CPPL and several chemical fertilizer options. The production of CPPL per kilogram was smaller than that of the chemical fertilizers; however, the environmental impact of chemical fertilizer production per kilogram of active substance (N, P2O5, or K2O) was lower for most impact categories, because the active substance was available at higher concentrations in said chemical fertilizers. In contrast, the NPK supply of a 100 ha field by CPPL was found to possess a smaller environmental impact compared to several combinations of chemical fertilizers. In conclusion, CPPL demonstrated its suitability as an alternative to chemical fertilizers.

The effects of fertilization on a 6 years old established grassland

The effects of fertilization on a 6 years old established grassland

Can nutrient‐utilization efficiency be improved by reduced fertilizer supply to maize plants treated with the plant growth regulator paclobutrazol?

AbstractIn previous investigations of several maize cultivars, an improvement of the harvest index was obtained by paclobutrazol (PAC) application combined with an increase in water‐use efficiency. However, so far nutrient‐utilization efficiencies could not be enhanced when control and PAC‐treated maize plants received the same amount of fertilizers. With adjusted fertilizer supply according to the lower requirement of the smaller, PAC‐treated plants, an improvement of nutrient‐utilization efficiencies may be expected. Thus, in the present study, PAC was applied at growth stage V5 to two maize cultivars (Zea mays L. cvs. Galactus and Fabregas) grown in a container experiment. Shortly after PAC application, differential NPK fertilization was introduced in order to obtain a nutrient supply according to the requirement of control plants (100% NPK), the requirement of PAC‐treated plants (85% NPK) and a further slight decrease (78% NPK). Plant height and transpiration rates were significantly reduced due to PAC treatment with stronger effects on Galactus than on Fabregas. Pollen shed, silking and the anthesis‐silking interval (ASI) were unaffected by PAC application and fertilizer supply. Senescence of PAC‐treated plants was delayed, whereas it was accelerated with reduced fertilizer supply. The grain yield of cultivar Galactus was significantly decreased due to PAC application by 13% to 20%, and this effect was strengthened due to reduction in NPK supply. These grain yield reductions were solely caused by decreases in kernel number, which were closely linked to reductions in cob length. On the contrary, PAC treatment did not affect grain yield of Fabregas and reductions due to less NPK supply were small. Harvest index and water‐use efficiency were enhanced by PAC treatment. Plant nutrient contents were similar for control and PAC‐treated plants, but strongly related to fertilizer supply with significant decreases due to reductions in NPK application. The N‐, P‐ and K‐utilization efficiencies of both cultivars were either decreased or unaffected by PAC treatments. The key constraint for improvements of nutrient‐utilization efficiencies is grain yield reduction due to PAC. This problem should be addressed in further studies with avoidance of grain yield decreases by delayed application time combined with fine‐tuning of cultivar‐specific PAC application rates.

Application of liquid formulation of a mixture of plant growth promoting rhizobacteria helps reduce the use of chemical fertilizers in Amaranthus (Amaranthus tricolor L.)

The efficacy of a liquid formulation of “PGPR mix-I″ amended with 15 mM treahoalose, and a talc based formulation of the same were tested for plant growth promotion in amaranthus crop in sterilized soil under glass house conditions. The seven treatments included 100% NPK as per Kerala Agricultural University recommendation as chemical fertilizer alone, talc based or liquid formulation of PGPR mix–I each alone and with 100% and 50% NPK, control with additive without plant growth promoting rhizobacteria and absolute control. Liquid formulation of PGPR mix–I was found to be equally effective as talc based formulation of PGPR mix–I along with 100% NPK chemical fertilizers in enhancing yield and other biometric parameters of amaranthus. Application of PGPR mix–I under 50% supply of NPK as chemical fertilizers was found to be on par with chemical fertilizer alone at 100% dose. Our results indicate that a saving of 50 percent of chemical fertilizer supply is possible by application of the improved formulation of PGPR mix-I in amaranthus.

Potassium humate amendment regulates soil NPK supply and growth parameters of potato (Solanum tuberosum L.) in a calcareous soil

Potassium humate amendment regulates soil NPK supply and growth parameters of potato (Solanum tuberosum L.) in a calcareous soil

The Use of Biostimulants in High-density Olive Growing: Quality and Production

Due to the increase of high-density holdings, especially of olive trees, the nutritional requirements of the plants are higher per unit area, which implies that a greater contribution of fertilizers to the soil is needed. Opting for fertilizers of inorganic origin will produce an increase in the pollution of the soil.
 In the face of this possible soil contamination, our aim is to analyze the effect of biostimulants as an alternative to chemical fertilizers, to steadily produce and maintain high quality standards during the life of the crop. Our objective is using more environmentally friendly products in order to satisfy one of the most important demands from both consumers and the authorities.
 In this study, we carried out five different treatments in addition to a control treatment with a supply of NPK, from inorganic products, which are used to control fertilization with a solution obtained from seaweed extracts. These treatments were applied in two crop cycles for two of the most important varieties in the current olive tree growing scenario: Arbequina and Koroneiki.
 This study was developed in the farm Pozohondo, which is located in a crop zone by the Palancia river (Castellón, Valencia, Spain), in the southeast of the Iberian Peninsula, where the olive trees were established in a high-density system with a planting framework of 4 x 1.5 m. We ensured an exhaustive control of the nutritional needs of the holding by using a fertigation system.
 We could notice differences in the productions of each applied treatment, avoiding any possible biases through the additional control of 100 randomly selected olives from each of the samples. There is an improvement in the set of physical characteristics of the olives with the treatment that provides amino acids and extra potassium based on amni acids. We analyzed the quality of the olive oil obtained from the production of each treatment by measuring the fatty acids, tocopherols and polyphenols contents. We also carried out an organoleptic tasting analysis following the rules of the International Olive Committee (IOC).
 We observed an improvement with regard to the rest of treatments in the pomological parameters of the olives when applying the potassium and amino acid biostimulant, while the quality of the oils was not affected by the type of fertilization applied in each treatment.

Productivity, Andrographolide, and NPK Content Influenced with Organics and Inorganics in Kalmegh

Core Ideas Integrated use of castor cake 2.5 t and NPK 80:30:50 kg ha–1 with split application of N (50% at TP and 50% in two splits at 25 and 40 DAP) produced highest dry herbage yield. Combined use of castor cake 2.5 t and NPK 80:30:50 kg ha–1 (50% N at TP and 50% at 25 DAP) recor–ded highest quality in terms of andrographolide content. Increased supply of NPK either through organics or inorganics showed positive and linear increase in andrographolide content. Kalmegh (Andrographis paniculata Nees) is being used since centuries in Asia as an alternative medicine to cure various health ailments. However, the quality, efficacy, and safety are major challenges due to lack of standard production protocols. A study was conducted with organic and inorganic nutrient sources, and split application of N to increase the herbage yield and quality as well, while maintaining/improving the soil fertility. Castor cake 2.5 t ha−1 recorded highest plant height, branches, and plant N and K content, whereas, P content was higher with vermicompost 7.5 t ha−1. Application of NPK 80:30:50 kg ha−1 with or without split application of N increased plant height and branches per plant, and plant NPK content. Interaction effects showed that combined use of castor cake 2.5 t ha−1 along with NPK 80:30:50 kg ha−1 and 2/3 split application of N recorded significantly higher herbage yield (8.1 t ha−1), and andrographolide content (24.2 mg g−1). Positive and linear regression [N (R2 = 0.64), P (R2 = 0.40) and K (R2 = 0.16)], and significant correlation [N (r = 0.80) P (r = 0.63) and K (r = 0.40)] at P = 0.01 were found between NPK applied and andrographolide content in plants. Vermicompost 7.5 t ha−1 and NPK 80:30:50 kg ha−1 (50% N in 2–3 splits) improved soil NPK content. Thus, integrated use of castor cake 2.5 t ha−1 along with NPK 80:30:50 kg ha−1 (N in 2/3 split applications) found optimum to harvest maximum commercial produce of better quality and improved soil fertility.

Ирина Яковлевна Маслова – заслуженный агрохимик ИПА СО РАН

The article describes professional biography of a remarkable researcher Doctor of Biological Sciences Maslova Irina Yakovlevna, who as an excellent agrochemist and soil scientist had worked in the Institute of Soil Science and Agrochemistry of the Siberian Branch of the (USSR) Russian Academy of Sciences since its establishment in 1968 until recently. In 1960 Maslova I. Ya. graduated from the Moscow Timiryazev’s Agricultural Academy as a specialist in soil science and agrochemistry and for several years afterwards studied soils in the Barabinsk lowland, the Kulunda steppe and northern forest-steppe zone in the Novosibirsk region in West Siberia. In 1963 Maslova I.Ya. became a post-graduate student in the Institute of Soil Science and Agrochemistry of the Siberian Branch of the USSR Academy of Sciences and started her own research of the agrochemical properties of leached chernozems in the near-Ob River area with a special focus on soil sulfur. Notably, in 1972-1984 Maslova I.Ya. participated in the State Inter-agency research program on ultra-potassium alumosilicate ores from the Synnyr mining site in the Central Siberia, studying in detail their potential use as a chlorine-free potassium fertilizer. Since 1976 Maslova’s research had been focused mainly on soil sulfur as during her studies in agroecosystems on podzolised chernozems and grey forest soils she found that under optimum NPK supply spring wheat did not reach expected yields even under favourable weather conditions due to, as further research showed, sulfur limitation. Since then Maslova became especially interested in this nutrient, mostly In 1983-1984 Maslova I.Ya., as a member of the joint expedition team studied meadow soils in the floodplain of the Orkhon River in Mongolia, actively teaching and advising Mongol specialists in Agrochemistry and soil science. In 1992 Maslova I.Ya. successfully proved her Doctoral thesis where she substantiated that spring wheat sulfur requirements depend on the rate of nitrogen supply, as additional nitrogen input results in available sulfur deficit, at first manifested in the grain quality, and then in the total yield. Maslova I.Ya. also concluded that soils of West Siberia are very diverse in relation to sulfur content, its speciation, profile distribution and plant availability, especially in the top soil horizons where sulfur can be found mostly in non-available form. To conclude, I. Ya. Maslova’s career as a steadfast, consistent and well focused one provides a perfect pattern for contemplation by young researchers.

Effects of Soil NPK Supply on Pinot noir Wine Phenolics and Aroma Composition

This work evaluated the impact of vine nitrogen (N), phosphorous (P), and potassium (K) supply on Pinot noir wine composition. Pinot noir grapevines were grown in a pot-in-pot system for three years and fertigated with varying levels of N, P, or K supply while holding all other nutrients constant. N was varied from 7.50 mM total N supply (Control) to as low as 1.125 mM total N in five discreet levels, while P and K supply were each varied in four levels, with the lowest rate (0 mM) during fertigation events. Wines produced in each of the three years were analyzed. N supply had a major impact on wine composition, including effects on volatile compounds, especially fermentation-derived esters and higher alcohols. Lower rates of N supply increased the total phenolic content in wine; in general, reduced N supply led to a decrease in straight-chain esters and alcohols, but to an increase in branched-chain esters and alcohols in wine. Low-N wines also had lower levels of volatile sulfur compounds in two of the three years. N supply also affected some grape-derived compounds in wine. Reducing N supply resulted in lower concentrations of β-damascenone across all years, but the effect of N supply on monoterpenes was not consistent from year to year. Altering P supply did not have reproducible effects on wine volatiles. Changes in volatile composition in response to nutrient supply could ultimately affect aroma perception and overall wine quality, which will require further exploration.

Vegetative, Chemical Status and Productivity of Zucchini Squash (Cucurbita pepo L.) Plants in Responses to Foliar Application of Pentakeep and Strigolactones Under NPK Rates

In order to determine the effect of two bio-stimulants under NPK fertilizer rates on growth and nutrient content and yield of zucchini (squash), an experiment was conducted at Mendel university during 2014. The treatments included four NPK rates namely, 0, 75, 100 and 150% of recommended rate in combination with foliar application of Pentakeep super and strigolactones (alone and in combination) were used. This study was arranged in a split plot design in three replications. The results showed NPK at 150% led to the maximum significant increase of growth characters i. e., leaf number, fresh and dry weight of leaves relative to unfertilized control. Chlorophyll reading increased significantly with increase in NPK supply up to NPK75%. The highest contents of N, K and nitrate were found in zucchini leaves treated with NPK at 150% of recommended rate. Yield and its component increased significantly with increase in NPK supply up to 100% of recommended rate. The combined application of Pentakeep super and strigolactones significantly maximized growth characters and fruit yield as compared to control treatment. The highest content of N generated in plants sprayed with Pentakeep super while application of Pentakeep and strigolactones did not affect the P and K contents. Whereas, control plants effectively significantly increased the chlorophyll and nitrate content of leaves.

Interactive Effects of N-, P- and K-Nutrition and Drought Stress on the Development of Maize Seedlings

Global climate change is likely to increase the risk of frequent drought. Maize, as the principal global cereal, is particularly impacted by drought. Nutrient supply may improve plant drought tolerance for better plant establishment during seedling growth stages. Thus, this study investigated the interactive effects of drought and the application of the nutrients N, P and K either individually or in combination. The maize seedlings were harvested between 12 and 20 days after sowing, and the leaf area, shoot fresh and dry weight and root dry weight were determined, and shoot water content and root/shoot dry weight ratio were calculated. Among the N, P and K fertilization treatments applied individually or in combination, the results showed that there was generally a positive effect of combined NPK and/or NP nutrient supply on shoot growth such as leaf area, shoot fresh and dry weight at day 20 after sowing under both well-watered and drought conditions compared with no nutrient supply. Compared with the effect of N and P nutrient supply, it seems that K was not limiting to plant growth due to the mineralogical characteristics of the illitic-chloritic silt loam used, which provided sufficient K, even though soil tests showed a low K nutrient status. Interestingly, the root/shoot ratio remained high and constant under drought regardless of NPK application, while it decreased with NPK applications in the well-watered treatment. This suggests that the higher root/shoot ratios with N, NP, PK and NPK under drought could be exploited as a strategy for stress tolerance in crop plants.

Management practices of macronutrients for potato for smallholder farming system at alluvial soil (Entisols) of India

ABSTRACTIn the present study, seven fertilizer treatments [T1, 50% NPK; T2, 100% NPK (Recommended dose of fertilizer, 200–65.4–124.5 kg N-P-K ha−1); T3, 150% NPK; T4, 100% PK; T5, 100% NK; T6, 100% NP and T7, control (zero NPK)] with four replications were assessed in the new alluvial soil zone (Entisols) of West Bengal, India. The objectives of the study were to generate information on potato productivity, profitability, indigenous nutrient supply and net gain/loss of NPK in post-harvest soil. Plants grown under higher NPK supply resulted in higher tuber yield and there were significant (p ≤ 0.05) reductions in total yield with nutrient omissions. Nutrient−limited yields were 19.78, 2.83 and 1.77 t ha−1 for N, P and K, considering total tuber yield (28.24 t ha−1) obtained under 100% NPK as targeted yield. Indigenous nutrient supply of N, P and K were estimated at 24.1, 22.34 and 110.22 kg ha−1, respectively that indicates higher K−supplying capacity of experimental soil as compared to N and P. Net income (US$1349 ha−1 year−1) and B:C ratio (1.91) was highest with 100% NPK, and further addition of NPK (150%) resulted in decrease on net return (US$1193 ha−1 year−1) and B:C ratio (1.73).

English

The objective of this research was to group C. canephora cv. Conilon coffee genotypes of different ripening cycles for both efficient absorption and utilization of N, P and K in contrasting environments. The experiment was arranged in a factorial scheme 13x4, with fours replicates, the factors being: 13 genotypes of Conilon coffee and four types of fertilization (NPK: 0%-100%-100%, 100%-0%-100%, 100%-100%-0% and 100%-100%-100% of the level recommended). The results indicated that conilon coffee genotypes have efficiencies to absorb and use N, P, K modulated by the availability of these nutrients in the soil, furthermore it was possible to assume that conilon coffee genotypes of early ripening cycle have high joint efficiencies of absorption and utilization in environment with adequate NPK supply. To optimize the nutritional management, the genotypes 67 and 76 would be recommended for plantations with low technological potential to better exploit their efficiencies of absorption and use of N, P and K; and the genotypes 02, 48 and 67 would be recommended for crops with high technological potential where, besides the nutritional efficiency, their responsiveness could be explored. For breeding programs, it is recommended the exploitation of conilon genotypes 02 and 67, for presenting simultaneously high absorption and utilization efficiency of NPK. Key words: Coffea canephora, mineral nutrition, fertilization, crop breeding.

Sustainable Technology for Using Bio-Waste in Rural and Urban Regions in South- and South-East-Asia

In many South-East-Asian countries is big lack of organic fertilizers for sustainable crop production, although there are many sources of biodegradable waste material. The best and sustainable way to convert the bio-waste from different sources in organic fertilizer is composting. Following our investigations, the supply of NPK is realized in Germany with about 40% by use of compost and in Vietnam with 1% only. Therefore, new organic sources are required and new technologies have to be developed in order to increase the amount of organic fertilizers. The available bio-wastes, have often high content of cellulose and lignin with slow decomposition rate. In order to enhance decomposition of such materials, specific microorganisms were added. For composting different types of container were used. Very good decomposition rate in short time were determined by use of a mix of different microorganisms and use of rotating containers.