Recommended Mineral Fertilizer Research Articles

Use of Organo-Mineral Fertilizers in Grain Sorghum as Reverse Logistics of Organic Residues

Organo-mineral fertilizers are an opportunity for technological innovation, because allow the correct disposal of waste from various agroindustrial sectors, which is a global problem, in order to add value to the by-product generated, as prioritized in reverse logistics. In this sense, the objective of this work was to evaluate the effect of organic matter sources on the composition of organo-mineral fertilizers in relation to the exclusive use of mineral fertilizers in cultivation of grain sorghum. The experiment was carried out at the Experimental Farm of the Federal Institute of the Triângulo Mineiro, located in the municipality of Campina Verde, State of Minas Gerais, Brazil. The experimental design was a randomized block with eight treatments and four replications arranged in a 4 × 2 + 2 factorial scheme, corresponding to: four levels of organo-mineral fertilizers (70, 100, 130 and 160% of the recommended dose of phosphorus), two sources of organo-mineral fertilizers (sewage sludge and filter cake), and two controls (without and with recommended mineral fertilization). The evaluations were: height of stem, number of leaves and stem diameter at 30, 60, and 90 days after sowing (DAS); total plant height; dry mass of plant shoot at 90 DAS, in vitro digestibility of organic matter at 90 DAS; the relationship of leaf area/ leaf and leaf area/ plant at 90 DAS. All parameters obtained a significant effect for the levels of organo-mineral fertilizer, independent of organic source, except to number of leaves and stem diameter. However, the relationship between the two organic sources was not significant just to plant height at 60 DAS. Interaction between fertilizer levels and organic source occurred to plant height at 90 DAS, dry mass per plant at 90 DAS and in vitro digestibility of organic matter. There was good adjustment in the quadratic regression equation for sorghum growth.

Tomato Yield and Economic Performance Under Vermicompost and Mineral Fertilizer Applications

Background:Optimum vermicompost and mineral fertilizer application is crucial for tomato production. However, farmers still use inadequate nutrient inputs and inefficient combinations. As a result, unbalanced soil nutrient compositions ultimately lead to a reduction in tomato fruit yield.Methods:An experiment was conducted to evaluate tomato yield and economic performance under vermicompost and mineral fertilizer applications using drip irrigation during 2016/2017. Shanti-PM variety of tomato was used as a test crop and eight vermicompost and mineral fertilizer combinations were laid out in a randomized complete block design with three replications. Agronomic data were analyzed using analysis of variance procedure. Besides, an economic analysis was carried out using partial budget analysis, to indicate economically superior treatments over the control treatment by estimating the varying costs and benefits based on the current local market prices for 2017.Results and Conclusion:Tomato fruit yield was markedly influenced by vermicompost and mineral fertilizer combinations. The better marketable, unmarketable and total fruit yield were recorded when 8 ton ha-1vermicompost combined with 50% recommended a dose of mineral fertilizer was applied. Even though this treatment appeared to be superior in yield, the results of partial budget analysis suggested that tomato cultivated using 4 ton ha-1vermicompost with 50% recommended mineral fertilizer was economically feasible to be acceptable by farmers. Therefore, application of 4 ton ha-1vermicompost with 50% recommended mineral fertilizer appeared to be agronomically superior and economically affordable for farmers to adopt.

Impact of Biocide, Insecticides, Compost and Mineral Fertilizers Treatments on the Abundance of Parasitoid and Predator Insects in Rice Fields

The present study was designed to investigate the effect of rice straw compost, recommended mineral fertilizers, Organic Insecticides and chemical Insecticides on the abundance pattern of natural enemies in rice ecosystems. To maximize rice productivity, rice growers tend to use chemical fertilizers and pesticides particularly to control different pest species, regardless of damage levels. Accordingly, rice fauna of natural enemies is severely impaired, leading to unbalanced rice ecosystems. The current investigation was carried out at the experimental farm of Rice Research and Training Center (RRTC), Sakha, Kafr El-Sheikh during 2016 and 2017 rice seasons. Using both D–Vac machine and pit–fall traps, parasitoids and predator insects were surveyed. Twelve hymenopterous parasitoid species were surveyed. Most of the parasitoid species were found belonging to Mymaridae, Trichogrammatidae and Braconidae. Twenty insect predator species, related to 13 families and seven orders, were identified, most of which are belonging to Coleoptera and Hymenoptera. Also this study aimed to surveying natural enemies (parasitoids and predator insects) and the effect of compost as an organic fertilizer on population densities of such beneficial insects. Although the application of insecticides successfully controlled insect pests, these chemicals have almost eradicated (more than 90 % reduction) the natural enemies. Biocide applications, especially Achook (Neem) and Tracer, achieved a considerable insect pest control, with population reductions of 33.30-57.32 and 10-46.01%, respectively. Unfortunately, the evaluated biocides induced mortalities to the considered natural enemies, but with too much less levels than did the insecticides. The current results indicate that the biocides could be applied to control rice insects in case of moderate insect infestations, with taking into consideration that they are not completely safe to the beneficial insects.

RESPONSE OF ONION PLANTS TO SOME SAFETY TREATMENTS IN THE FIELD.

The present experiments included six treatments the were randomly arranged using the complete randomized design with four replicates. Mycorrhiza achieved the best records of plant height and leaves and neck fresh weight. Seaweed, mycorrhiza and magnetic water irrigation attained the records of number of leaves. Plant received mycorrhiza followed by those received magnetic water irrigation gained, in general bulb dry weight. As for growth analysis attributes, all of the applied treatments, excepting organic manure at the first period, positively affected leaf area and leaf area index. As for chemical constituents, all applied treatments unsignificantly increased P and K contents. Significant positive correlations were, generally, observed between chlorophyll fractions and the tested treatments. The correlation between of the tested treatments and the accumulation of different biochemical active compounds within treated onion such as ploy phenols, peroxidases and cinamic acid substrates were investigated through using HPLC apparatus. The results showed that the highest recorded growth and vegetative criteria were observed on plants treated with mycorrhiza fungi followed by magnetized water. On contrary, the lowest growth and vegetative values were recorded by organic fertilizers and traditional recommend fertilizers. Biochemical analysis using HPLC revealed that cinamic acid substrate was detected only within treated plants by sea weeds extracts, humic acid and recommended mineral fertilizers. The highest accumulation of peroxidase enzyme was observed with mycorrhiza and sea weeds treatments. The results showed also that mycorrhiza fungi, sea weeds extracts, organic fertilizers in addition to recommend mono fertilizers increased the accumulation of poly phenols substrates more than all other tested treatments. As for bulbs yield and yield components, all applied treatments failed to achieve any significant effect on both bulbs diameter or length. As for the total yield, mycorrhiza followed by magnetic water achieved the highest record in the connection as seaweed occupied the third position. As for bulbs storageability, excepting for magnetized water and humic acid, which reduced weight loss in all assessing dates, all applied treatments caused, in general, an increase in this storage attribute.

PHYSIOLOGICAL AND BIOCHEMICAL INFLUENCES OF SOME SAFETY TREATMENTS ON ONION PLANTS

Effects of five different non-traditional treatments i.e. magnetic water, humic acid, seaweeds extracts, mycorrhzyia fungi and organic fertilizers in addition to the traditional mineral recommended fertilizer were determined in aspect to different growth characteristics within onion plants grown in two subsequent seasons under open field conditions in station of faculty of agricultural at minufiya university. The correlation between of the tested treatments and the accumulation of different biochemical active compounds within treated onion such as ploy phenols, and peroxidases substrates were investigated through using HPLC apparatus. The results showed that the highest recorded growth and vegetative criteria were observed on plants treated with mycorrhyza fungi followed by magnetized water. On contrary, the lowest growth and vegetative values were recorded by organic fertilizers and traditional recommend fertilizers. Biochemical analysis using HPLC revealed that cinamic acid substrate was detected only within treated plants by sea weeds extracts, humic acid and recommended mineral fertilizers. The highest accumulation of peroxidase enzyme was observed with mycorrhyza and sea weeds treatments. The results showed also that Mycorrhyza fungi, sea weeds extracts, organic fertilizers in addition to recommend mono fertilizers increased the accumulation of poly phenols substrates more than all other tested treatments.

Response of fodder sorghum (Sorghum bicolor (L.) to sewage sludge treatment and irrigation intervals in a dryland condition

A field experiment was conducted in the Experimental Research Farm of Omdurman Islamic University, Sudan to determine short-term effect of irrigation intervals (7 and 10 days) and sun-dried or composted sewage sludge, recommended mineral fertilizer on straw dry matter yield (SDMY) and N, P and K content of fodder sorghum and soil properties. In the 7 and 10 days irrigation intervals, composted, sun-dried sludge and mineral fertilizer have significantly increased SDMY over the control by 51, 98, 67 and 78, 19, 33%, respectively. Apparent N use efficiency (ANUE) in composted and sun dried plots irrigated at either 7 or 10 days was 9 - 36 and 16 - 74%, respectively. Reducing the irrigation interval has significantly increased salinity by 13%. Increasing irrigation interval has decreased bulk density by 5%. It could be concluded that, application of composted sludge is a useful practice for improvement of soil properties and consequent yield increase.

Yield and quality of ‘Italia’ grapes submitted to irrigation and fertilization control at the San Francisco Valley, Brazil

The aim of this research was to evaluate aspects related to flowering, fruiting and quality of ‘Italia’ grape produced under different irrigation and fertilization. The experiment was performed from October, 2014 to February, 2015, in a production area of 0.50 ha at IFSERTÃO-PE, in Petrolina-PE, Brazil. The experiment was carried out in a randomized blocks design, with a split block scheme, with four irrigation treatments (plots), four fertilizer treatments (subplots) and four repetitions. The plots consisted of the multiplying factors, 0.75 (L1); 1.00 (L2); 1.25 (L3) and 1.50 (L4), of the recommended crop coefficients (Kc) by Embrapa Semi-Arid for the ‘Italia’ grapevine. The subplots were composed by the factors 1.00 (AD1), 0.75 (AD2), 0.50 (AD3) and 0.25 (AD4) of the recommended fertilization with an BIOSON as organic product (commercial name). It was observed that the reduction in water depth provided greater number of buds per branch and a larger number of clusters per plant. The highest yields were obtained with lower irrigation depths and 50% and 65% of the recommended fertilization. The highest soluble solids of the fruit were achieved using the 75% of irrigation Kc and 25% of recommended mineral fertilization. The lower total acidity values were obtained with the Kc multiplication factors that were lower than 1.04 and higher than 1.22.

Guava Waste to Sustain Guava (Psidium guajava) Agroecosystem: Nutrient "Balance" Concepts.

The Brazilian guava processing industry generates 5.5 M Mg guava waste year−1 that could be recycled sustainably in guava agro-ecosystems as slow-release fertilizer. Our objectives were to elaborate nutrient budgets and to diagnose soil, foliar, and fruit nutrient balances in guava orchards fertilized with guava waste. We hypothesized that (1) guava waste are balanced fertilizer sources that can sustain crop yield and soil nutrient stocks, and (2) guava agroecosystems remain productive within narrow ranges of nutrient balances. A 6-year experiment was conducted in 8-year old guava orchard applying 0–9–18–27–36 Mg ha−1 guava waste (dry mass basis) and the locally recommended mineral fertilization. Nutrient budgets were compiled as balance sheets. Foliar and fruit nutrient balances were computed as isometric log ratios to avoid data redundancy or resonance due to nutrient interactions and the closure to measurement unit. The N, P, and several other nutrients were applied in excess of crop removal while K was in deficit whatever the guava waste treatment. The foliar diagnostic accuracy reached 93% using isometric log ratios and knn classification, generating reliable foliar nutrient and concentration ranges at high yield level. The plant mined the soil K reserves without any significant effect on fruit yield and foliar nutrient balances involving K. High guava productivity can be reached at lower soil test K and P values than thought before. Parsimonious dosage of fresh guava waste should be supplemented with mineral K fertilizers to recycle guava waste sustainably in guava agroecosystems. Brazilian growers can benefit from this research by lowering soil test P and K threshold values to avoid over-fertilization and using fresh guava waste supplemented with mineral fertilizers, especially K. Because yield was negatively correlated with fruit acidity and Brix index, balanced plant nutrition and fertilization diagnosis will have to consider not only fruit yield targets but also fruit quality to meet requirements for guava processing.

Pig slurry composting as a nitrogen source in proso millet crop

ABSTRACT With the intensification of pig farming systems, in Brazil, the production of swine waste has increased considerably, leading to water and soil contamination, due to its improper release. Pig slurry composting is an alternative that can be used in order to avoid or reduce negative impacts, especially for producers with physically limited farm areas, or those who intend to increase the number of animals in their production units. This study aimed at evaluating the influence of pig slurry compost doses on the agronomic characteristics and grain yield of proso millet. A randomized blocks design experiment was installed with four replications and five treatments: control without fertilization, control with mineral fertilizer (NPK) and pig slurry compost doses (4.0 Mg ha-1, 8.0 Mg ha-1; 12.0 Mg ha-1). The pig slurry composting increased the dry matter yield, number of grains per plant and grain yield of proso millet, when compared to the control with or without mineral fertilizer. The proso millet yield, at the doses of 8.0 Mg ha-1 and 12.0 Mg ha-1 of pig slurry, was superior than for both the control without fertilization and the control with the recommended mineral fertilizer, with the latter reaching a maximum agronomic efficiency at the dose of 8.0 Mg ha-1.

Estoques de Carbono e Nitrogênio e Densidade do Solo em Sistemas de Adubação Orgânica de Café Conilon

RESUMO A produção de café conilon em sistemas de manejo orgânico tem aumentado no Estado do Espírito Santo. Porém, faltam informações sobre o impacto desse manejo sobre os estoques de carbono e nitrogênio do solo. Este trabalho teve como objetivo avaliar o efeito da adubação orgânica sobre os estoques de C e N e a densidade do solo (Ds) em agrossistema de café conilon. O experimento foi implantado em lavoura localizada no município de Linhares, ES, no delineamento em blocos casualizados com distribuição fatorial 2 × 2 × 5, com três repetições, sendo os fatores: dois compostos orgânicos; presença e ausência da leguminosa feijão-de-porco nas entrelinhas; e cinco proporções de cada composto em substituição à adubação mineral recomendada (0; 25; 50; 75; e 100 %). Cada repetição foi formada por amostragem de solo sob a copa de uma planta em parcela com 30 cafeeiros. Os compostos foram: composto 1, preparado com capim-elefante e palha de café na proporção 1:1 (v:v); e composto 2, preparado com capim-elefante, palha de café e cama de frango na proporção 2:1:1 (v:v:v). As coletas de solo foram realizadas 240 dias após a adubação (240DAPA) do 1º ano agrícola e aos 30 dias após a 1ª etapa da adubação (30DAPA) do 2º ano agrícola. O uso de composto na adubação do cafeeiro acarretou redução da Ds de aproximadamente 13 %. O incremento das proporções de compostos na adubação aumentou o teor e o estoque de C e N do solo aos 30DAPA do 2º ano agrícola. Houve acréscimos de 11 e 0,4 Mg ha-1 para o estoque de C e N, respectivamente, para cafeeiros adubados com 100 % de composto 1, em relação à adubação mineral. A adubação com composto é alternativa para aumentar os estoques de C e N no agrossistema de conilon.

MINIMIZING STRAWBERRY MINERAL FERTILIZATION AND ENHANCING WATER USE EFFICIENCY BY USING MAGNETIZED IRRIGATION WATER

This study was carried out at Al-Kanater Research Station, El-Kaluobia Governorate during the two successive seasons of 2012-2013 and 2013-2014, to investigate the effect of magnetized water on minimizing strawberry mineral fertilization. Four treatments were used i.e., tap water plus 100 % NPK (control), magnetized water plus 50 % NPK, magnetized water plus 75 % NPK and magnetized water plus 100 % NPK of the recommended mineral fertilization rates. Data were recorded on some vegetative growth characters, early and total fruit yield, some physical and chemical fruit quality parameters and macro and micro elements in leaves. Results indicated that irrigation with magnetized water plus 50% NPK of the recommended fertilization rate showed the highest values of total chlorophyll, total carbohydrates, early and total yield, fruit firmness, total soluble solids in fruits and water use efficiency as compared with control. Moreover, magnetized water plus 75% NPK of the recommended rate of mineral fertilization showed the highest values of NPK and manganese contents. In general ascorbic acid was decreased by using magnetized water. The study recommend using 50 % of the recommended NPK fertilization rates plus magnetized water to increase yield and quality of strawberry.

Impact of Bio- and Organic Fertilizers on Potato Yield, Quality and Tuber Weight Loss After Harvest

This study was conducted to assess whether organic fertilization alone or with bio-fertilization could replace mineral fertilization in potato production with no adverse effect on quantity or quality. Therefore, two field experiments were conducted at Maba Farm, Cairo—Alexandria Desert Road in Egypt to evaluate the impact of mineral, organic, and bio-fertilizers on a sandy soil on yield, quality, and weight loss after harvest of potato tubers. Control plots were treated with recommended rates of mineral fertilizer + 11.9 t ha−1 compost and the other treatments were 23.8 t ha−1 compost, 23.8 t ha−1 compost + bio-fertilizer, 11.9 t ha−1 compost + bio-fertilizer, 50% of mineral fertilizers + 23.8 t ha−1 compost, 50% of mineral fertilizers + 23.8 t ha−1 compost + bio-fertilizer, 50% of mineral fertilizers + 11.9 t ha−1 compost + bio-fertilizer, and 35.7 t ha−1 compost. There were significant increases in the total and marketable yield of potato crops from plots treated with 50% of the recommended mineral fertilizers plus 23.8 t ha−1 compost with or without bio-fertilizer as well as from plots that received compost at the rate of 35.7 t ha−1, compared with plots treated with full dose of mineral fertilizer plus 11.9 t ha−1 compost (control). Compost at 23.8 t ha−1 + bio-fertilizer resulted in a significant increase in marketable yield. Nevertheless, total yield obtained from plots treated with compost at 23.8 t ha−1 alone or plus bio-fertilizer did not differ significantly from the conventional control treatment. Compared with conventional fertilizer treatment, plots receiving compost at 23.8 t ha−1 alone or at 11.9 t ha−1 plus 50% mineral fertilizers and bio-fertilizer showed a lower nitrate content in potato tubers. Bio-fertilizer + organic fertilizer at a rate of 11.9 t ha−1 reduced marketable yield by 11.8% and total yield by 9.2%, compared with using organic fertilizer at a rate of 23.8 t ha−1 compost. So, for export of organic potato, which is characterized by 2–3-fold higher product prices, bio-fertilizer in the present study could not be an alternative to organic fertilizer. The highest nitrate content of tubers was obtained in control plots and plots that received 35.7 t ha−1 compost. Conventional fertilizer showed significantly higher weight loss of potato tubers during cold storage than all other treatments. Tuber K content was low in organic potato, whereas no effect was recorded on tuber N, P, or starch content. Hence, these results suggest that organic production of potato (at the level of 23.8 t ha−1 compost) could be an alternative to conventional production without significant reduction in yield, and with low nitrate content and better storability.

Trocas gasosas e teores foliares de NPK em meloeiro adubado com biofertilizantes

The aim of this study was the evaluation of biofertilizing with different biofertilizer types applied in different doses. We tested gas exchanges and leaf NPK contents on the melon plant (Cucumis melo L.). The experiment was conducted at the experimental area of the UFC (Universidade Federal do Ceará), in Fortaleza, in the period from September (2011) to December (2011). The experimental design was that of randomized blocks in a factorial 2 × 4 + (2) arrangement, corresponding to two types of liquid biofertilizer (mixed aerobically fermented biofertilizer and simple anaerobically fermented bovine biofertilizer) and four fertilizer doses (0.5, 1.0 , 1.5 and 2.0 L plant-1 week-1), with two additional treatments (control and recommended mineral fertilization). We analyzed the following variables: transpiration, stomatal conductance, photosynthesis and leaf Nitrogen (N) content, leaf phosphorus (P) content and leaf potassium (K) content. Plants biofertilized with simple bovine biofertilizer showed higher photosynthetic and transpiration rates, while the mixed biofertilizer was more efficient in terms of stomatal conductance. The simple bovine biofertilizer provided higher leaf phosphorus contents, while mixed biofertilizer provided higher leaf nitrogen and leaf potassium contents, when compared to control and to mineral fertilization. At the end of the production cycle, the plants fertilized with mixed biofertilizer and simple were supplied in N and P, and deficient in K.

Yield and nutritional status of the conilon coffee tree in organic fertilizer systems

The conilon coffee tree presents high yield potential, the replacement of soil nutrients usually being by the use of mineral fertilizers. To reduce these fertilizers, the use of organic waste may be an alternative. The objective of this study was to evaluate the effect of organic fertilizer systems on the nutritional status and yield of the conilon coffee tree. On a farm, located in the town of Linhares, Espirito Santo, during the agricultural year of 2009/2010, a trial was set up using a completely randomized block design with a factorial distribution of 2 x 2 x 5 and three replications, the factors being: organic compost (compost 1 and compost 2 ); legumes (the presence and absence of jack beans, sown between the rows of coffee trees); and the proportions of each compost (0; 25; 50; 75 and 100%) as a substitute for the recommended mineral fertilizer. The increase in the proportion of compost 2 was reflected as increases in the P content of the leaves due to the higher concentration of this nutrient in the compost. The increase in compost input increased the S content of the leaves as a response to the increase in soil pH. Maximum values of 61 and 66 sacks ha-1 were obtained with substitutions (mineral source by organic) in the proportion of 40 and 37% for compost 1 and compost 2 respectively. The use of organic-waste composts is an alternative as a partial replacement of mineral fertilizers in the conilon coffee tree, resulting in increases in yield.

Uncovering the Footprints of Erosion by On-Farm Maize Cultivation in a Hilly Tropical Landscape

A hilly region in Sri Lanka was considered to be degraded by erosion driven by intensive tobacco production, but what are reliable indicators of erosion? In addition to determining soil chemical and physical traits, maize was cropped with Nitrogen, Phosphorus and Potassium (NPK, PK) recommended mineral fertilization and without fertilizer (ZERO) in two major seasons(October–January in 2007/2008 and 2008/2009—Seasons 1 and 2 respectively) on 92 farms at inclinations ranging from 0% to 65%. In a subset of steep farms (n = 21) an A horizon of 6 cm rather than of 26 cm was strong proof of erosion above 30% inclination. Below the A level, the thickness of the horizon was unaffected by inclination. Soil organic matter contents (SOM) were generally low, more so at higher inclinations, probably due to greater erosion than at lower inclination. Maize yields decreased gradually with increasing inclination; at ZERO, effects of climate and soil moisture on yield were easier determined and were probably due to long-term erosion. However, despite an initial set of 119 farms, an exact metric classification of erosion was impossible. NPK strongly boosted yield. This was a positive sign that the deficits in chemical soil fertility were overriding physical soil weaknesses. The study illustrated that chemical soil fertility in these soils is easily amenable to modifications by mineral and organic manures.

Yield Responses of Maize to Organic and Mineral Fertilizers at Different Inclinations in Tropical Smallholder Farming Systems

A field study was conducted on the potential of Gliricidia (Gliricidia sepium (Jacq.) Kunth ex Walp.) to enhance productivity of degraded soils. Maize was cropped in a hilly region of Sri Lanka with and without the recommended mineral fertilization, in two major seasons, October-January in 2007/8 (Year 1) and in 2008/9 (Year 2) on 92 farms at two inclinations: Flat (0-10%) and Moderate (10-30%). On half the farms, green manure (Gliricidia leaves) was added (3 tonnes per hectare per season). NPK boosted production to a very respectable mean grain yield of 4.2 t/ha on Flat farms. At ZERO, the yield was lower by 60%, irrespective of the inclination. Gliricidia failed to replace the required nitrogen, even with an adequate supply of phosphorous and potassium (PK). In contrast, together with NPK, Gliricidia increased yields by 15-20% compared to NPK alone, while the gain was 35% at ZERO. Fields in the Moderate category were more responsive to green manure and mineral fertilizers. The high response to mineral fertilizers indicated that the degradation of the soils resulted to a greater extent in chemical rather than in physical deficits. But intensive cropping reduced the soil organic matter within two years, to some extent slowed down by Gliricidia green manure. Therefore an intense cropping for the sake of food security must be accompanied by soil conserving cropping systems.

Considering winter cover crop selection as green manure to control methane emission during rice cultivation in paddy soil

Cover crop cultivation during the cold fallow season has been strongly recommended in mono-rice cultivation system to improve soil quality. Its addition as green manure could stimulate methane (CH4) emission in the submerged paddy soil during rice cultivation, but its effect has not been evaluated well. Leguminous Chinese milk vetch (hereafter milk vetch) and non-leguminous rye were seeded after rice harvesting in 2008 and 2009, and total above-ground biomasses were incorporated with the recommended mineral fertilizers (NPK+milk vetch, and NPK+rye, respectively) before rice transplanting in 2009 and 2010. No fertilization (control) and mineral fertilization alone (NPK) plots were installed for comparison. Methane flux which was investigated by the closed chamber method during rice cultivation was significantly increased by chemical fertilization to ca. 80–250% over the control (138–141kgCH4ha−1), but increased more markedly by cover crop biomass addition to ca. 28–121% over the NPK treatment. Milk vetch was more effective on stimulating less CH4 emission (28–61% increase over NPK) and improving rice productivity (18–31% increase over NPK) than rye (86–121% increase of CH4 emission and −3–6% of yield increase over NPK). As a result, the total CH4 flux per grain yield was significantly increased by rye addition, but were similar between the NPK+milk vetch and NPK treatments. Conclusively, low C/N ratio cover crop like milk vetch might be more recommendable green manure to minimize CH4 emission impact and increase rice productivity than high C/N ratio cover crop like rye in paddy soil.

Effect of swine residue rates on corn, common bean, soybean and wheat yield

Swine residue (SR) applied as nutrient source of crops such as corn, bean, soybean and wheat, besides representing an environmental-friendly way of disposing of organic waste resulting from swine production, may significantly increase grain yields, replacing mineral fertilizer. The objective was to evaluate the effect of SR rates on corn, common bean, soybean and wheat yields from 2002 to 2007, in comparison with mineral fertilizer. The experiment was carried out at the Instituto Agronômico do Paraná - IAPAR, Pato Branco, PR and consisted of increasing SR rates (0, 15, 30, 45, and 60 m³ ha-1) and one treatment with mineral fertilizer (NPK 4-30-10), using 250 kg ha-1 for bean and 300 kg ha-1 for corn, soybean and wheat. Also, in the treatment with mineral fertilizer, 60, 120 and 90 kg ha-1 N was applied as topdressing to bean, corn and wheat, respectively. There were significant increases of grain yield in all evaluated years and crops with increasing SR rates, especially in the grass species under study. Also, with increasing SR rates applied every six months, K, P, Ca and Mg were accumulated in the soil and the pH increased. The application of 60 m³ ha-1 SR increased yields and exceeded the yield obtained with the recommended mineral fertilizer, indicating this amount as adequate for these crops.

Atividade microbiana e enzimática em solo após a aplicação de xisto retortado

O objetivo deste trabalho foi avaliar o efeito da aplicação de doses crescentes de xisto retortado (XR) sobre características biológicas indicadoras da qualidade do solo. Foram realizados experimentos, em Argissolo Vermelho distrófico arênico, em condições de laboratório e de campo. Em laboratório, os tratamentos consistiram da aplicação ao solo de sete diferentes doses de XR (0, 300, 450, 600, 750, 1.500 e 3.000 kg ha-1). Em campo, os tratamentos foram compostos por quatro diferentes doses de XR (0, 750, 1.500, 3.000 kg ha-1) combinadas à adubação mineral recomendada, avaliados em dois cultivos de feijão (Phaseolus vulgaris L.), no sistema plantio direto. Avaliaram-se: a evolução de CO2, o carbono da biomassa microbiana (CBM), a atividade enzimática do solo e o teste de ecotoxicidade. A aplicação de doses crescentes de XR melhorou a atividade microbiológica do solo, por reduzir a emissão de CO2 sem causar variação no CBM e sem provocar impactos negativos sobre a atividade enzimática do solo. Os resultados obtidos com as enzimas em condições de campo, após duas aplicações de XR, aliados aos de CBM, do quociente metabólico (qCO2) e do teste ecotoxicológico, em condições de laboratório, indicam que o uso do XR não provoca a degradação biológica do solo.

Impact of Locally Derived Organic Materials and Method of Addition on Maize Yields and Nitrogen Use Efficiencies in Major and Minor Seasons of Tropical South Asia

Maize is the most important highland cereal grown in the tropics, generally cultivated under rainfed smallholder conditions in Asia. Field experiments were carried out in Sri Lanka with the objective of determining the impact of three types of organic matter applied as mulch or incorporated on the yields and nitrogen uptake by maize cultivated under rainfed conditions in the South Asian major and minor seasons. The organic matter used was leaves of Gliricidia sepium, Tithonia diversifolia, or rice straw, with the full compliment of recommended mineral fertilizers. Organic matter, especially the two green manures, enhanced yields and nitrogen (N) uptake of maize, and the impact was more prominent in the minor dry season where the yields were lower. Incorporation of organic matter had a greater positive impact in the dry season in terms of N utilization efficiency and seed yields. The beneficial impact of organic matter with low carbon (C):N ratios in enhancing N nutrition and seed yields of rainfed maize in major and more importantly in the minor seasons is presented.