Biochar Phosphate Fertilizer Loaded with Urea Preserves Available Nitrogen Longer than Conventional Urea

Biochar, a carbon-rich material obtained by pyrolysis of organic wastes, is an attractive matrix for loading nutrients and producing enhanced efficiency fertilizers. In this study, poultry litter (PL) was enriched with phosphoric acid (H3PO4) and MgO to produce a biochar-based fertilizer (PLB), which was loaded with urea in a 4:5 ratio (PLB:urea, w/w) to generate a 15–15% N–P slow-release fertilizer (PLB–N) to be used in a single application to soil. A greenhouse experiment was carried out in which a common bean was cultivated followed by maize to evaluate the agronomic efficiency and the residual effect of fertilization with PLB–N in Ultisol. Six treatments were tested, including four doses of N (100, 150, 200, and 250 mg kg−1) via PLB–N in a single application, a control with triple superphosphate (TSP—applied once) and urea (split three times), and a control without N-P fertilization. The greatest effect of PLB–N was the residual effect of fertilization, in which maize showed a linear response to the N doses applied via PLB–N but showed no response to conventional TSP + urea fertilization. Biochar has the potential as a loading matrix to preserve N availability and increase residual effects and N-use efficiency by plants.

Tillage effect on agronomic efficiency of nitrogen under rainfed conditions of Tanzania.

Nitrogen (N) deficiency is a common feature in soils managed by smallholder farmers in Africa. Crop residue retention, in combination with no-till (NT), may be a pathway to improve agronomic use efficiency of applied N for small-scale farmers under the predominant rainfed conditions. This chapter reports on the results of a study carried out over two cropping seasons in the long rains of 2014 and 2015 on two sites: (i) on-farm (Mandela); and (ii) a research station (SARI) in eastern Tanzania. The experiment consisted of two tillage systems, conventional tillage (CT) and Conservation Agriculture (CA), with a minimum of 2.5 t ha-1 crop residue cover maintained in the plots during the experiment. CT consisted of soil inversion through tillage and removal of crop residues. In the on-farm experiment, maize was grown in plots with four rates of N application: 0, 27, 54 and 108 kg N ha-1. In the on-station trial, five rates were used: 0, 20, 40, 60 and 100 kg N ha-1. Maize yield and agronomic efficiency (AE) of N were used to assess and compare the productivity of the tested treatments. The results showed that tillage, soil type and rate of N application influenced crop productivity. In the clay soils, the differences between tillage practices were small. Under CT, AE ranged between 21.6 and 53.9 kg/kg N, and it was 20.4-60.6 kg/kg N under CA. The lowest fertilizer application rate of 27 kg ha-1 often had the largest AE across the soil types and tillage practices. In the on-station trials at SARI, the largest AE of 24.6 kg/kg N was recorded under CA with 40 kg N ha-1. As in the on-farm trials, the highest N application rate on-station did not lead to the largest AE. In the CT, AE ranged between 11.5 and 16.8 kg/kg N compared with a range of 15.1 to 24.6 kg/kg N for the CA treatment. Overall, crop residue retention, in combination with NT, is important to improve soil moisture and use efficiency of applied nutrients. Additionally, the initial soil fertility status is also important in determining the magnitude of short-term crop response to applied nutrients. Innovative pathways are needed to achieve the multiple objectives played by maize crop residues for results reported here to be sustainable. However, efficiency of nutrient use needs to be assessed, together with returns on investments, as small yields may mean high nutrient use efficiency but not necessarily significant increased returns at the farm level.

Environmental Impacts, Human Health, and Energy Consumption of Nitrogen Management for Maize Production in Subtropical Region

Over-application of fertilizers could not improve crop yield and agronomic efficiency, but result in increasing nitrogen (N) surplus and adverse effects on the ecosystem sustainability. Although some previous studies have addressed one or a few environmental aspects in crop production, an integrated assessment for the effects of N fertilizer on multiple environmental impacts, and the optional steps of normalization and weighting is required. A consecutive 2-yr plot-based field experiment was conducted with five N fertilizer levels (0, 90, 180, 270, and 360 kg N ha-1) in maize production at three sites in Southwest China, to evaluate the environmental performance and sustainability through joint use of life cycle assessment (LCA) and energy consumption analysis. Results demonstrated that the optimal N rate (180 kg N ha-1) showed greater potential for maintaining high yield (achieved 86% of the yield potential) and reducing the global warming (-31%), acidification (-47%), eutrophication (-44%) compared to farmers’ practice, and energy depletion potentials, by reducing pollutants emission during the production and transportation of N fertilizer and Nr losses at farm stage. Optimal N treatment indirectly reduced the land use, life-cycle human toxicity, aquatic eco-toxicity, and terrestrial eco-toxicity potentials by improving grain yield and agronomic efficiency. In addition, the optimal N treatment reduced the energy consumption by enhancing the energy use efficiency (EUE) (+74%) and reducing non-renewable energy form (-45%) than the farmer’s practice. This study will provide comprehensive information for both scientists and farmers involved in maize production and N management in subtropical region.

Effects of Nipping and Micronutrient Foliar Application on Dry Matter Production, Yield, Agronomic Efficiency and Nutrient Uptake of Short Duration Pigeonpea (Cajanus Cajan L.) Co(Rg)- 7

Background The productivity of pulse crop is low due to cultivation on agriculturally marginal and sub marginal lands under poor management. So, it needs earnest attention in adaption of desirable production technologies to exploit the yield potential of the pulses and it can be possible by application of fertilizers, nipping and foliar application of nutrients.In this view, aresearch was conducted to studyyield maximization, agronomic efficiency and nutrient uptake pattern with nipping and nutrient management practices in irrigated pigeonpea.Methods Field experiment was conducted at farmer’s field, Palacode, Palacode Taluk, Dharmapuri District.The pigeonpea seeds were sown by adapting a spacing of 45 × 30 cm. Entire dose of N, P2O5 and K2O (25: 50: 25 kg)were applied basally and the foliar spraying of 0.5 per cent Micronutrient mixture was done as per treatment schedule on 30th& 45th days after sowing using Knapsack Sprayer with the spray fluid of 500 lit. ha-1.Results The results revealed that the application of T9 (125% RDF + Nipping + Micronutrient) recorded significantly higher dry matter production, yield and nutrient uptake.The least values were recorded under the treatment T1 (Control).

Beetroot and radish production under different doses of green manures

Green manuring with spontaneous species from Caatinga biome has become an important strategy in production vegetables. One of the great challenges in tuberous vegetables production is to define an optimized quantity that provides a high productive yield with economic efficiency of production system. The objective of this study was to optimize agronomically and economically the production and its components of tuberous crops of beetroot and radish when manured with different amounts of green manures biomass, Merremia aegyptia and Calotropis procera from Caatinga biome, in two cropping seasons. The experimental design was a randomized complete block with five treatments and five replications. Treatments consisted of green manures amounts (16, 26, 36, 46, 56 t ha-1). The maximum agronomic efficiency of beetroot and radish was obtained with incorporation of 49.87 and 39.43 t ha-1 of M. aegyptia and C. procera, respectively, and the production maximum economic efficiency was reached when 36.14 and 36.48 t ha-1, respectively, of biomass of these green manures were added to the soil. The returns rate obtained in beetroot and radish cultivation using the manures optimized amounts were 1.42 and 1.32 reais obtained for each real invested in the production of these tuberous.

Effect of Silicon Nutrition on Yield, Uptake and Agronomic Efficiency of Paddy in Acid Lateritic Soils of Odisha

A field experiment was conducted in the central farm, Regional Research and Technology Transfer Station, Coastal Zone OUAT, Bhubaneswar during kharif 2020 using cv-Lalat variety of Rice. The experiment was laid out in randomized block design (RBD) with ten treatments and three replications. In this experiment BOF (Basic Oxygen Furnace) slag was used as a source of silica for application to rice crop. 200, 300 and 400 kg SiO2/ha was applied in combination with 50% STD and 75% STD in order to assess the efficacy of Silica with reduction in fertilizer dose by 50% and 25%. It was shown in case of grain yield, straw yield, and harvest index, 100% STD (T4) registered maximum (36.9q/ha) grain yield which was 29.4% more than that of control. Of course, grain yield in case of T9i.e., 75% STD+300kg SiO2/ha was at par 36.2q/ha indicated efficacy of silica application by reducing fertilizer dose. Harvest index was not significantly affected by Si treatments. However, maximum HI (0.478) was observed in T9. Available N, P, K and S status in post-harvest soil was increased significantly due to application of silica along with fertilizer over control indicated better availability of nutrients which plays a vital role in increasing production and productivity of rice. The content and uptake of N, P, K and Si was significantly increased over control due to application of silica with fertilizer. Though 100% STD (T4) was found to be very effective as compared to other treatments but 75% STD+300kgSiO2/ha was also equally effective so far as yield, yield attributing characters, available nutrient status, N, P, K and Si content and uptake along with Relative Agronomic Efficiency (RAE), Agronomic Efficiency (AE), Apparent Recovery (%) AR and Production Efficiency (PE) are concerned.

Productivity of lettuce in greenhouse as affected by humic and fulvic acids application in association to mineral fertilizer

ABSTRACT Humic substances (HS) have proved to be effective in improving the productivity of vegetable crops. We examined the effect of commercial biostimulants rich in humic (HA) and fulvic acids (FA) obtained from leonardite on agronomic efficiency and nutrient content in the leaves of lettuce (Lactuca sativa). A greenhouse experiment was carried out employing 2.5-L pots containing Ultisol samples that were supplied with commercial biostimulants rich in HA and FA, alone and in combination with NPK mineral fertilizer. The application of HS biostimulants associated to mineral fertilization to the lettuce plants provided the greatest values of the studied variables, namely: plant height and diameter, leaf number per plant and root length. The combination of FA biostimulants and mineral fertilization increased the lettuce productivity relative to the inorganic fertilizer alone. The combined application of rich biostimulants FA and HA with NPK fertilizes influenced K and Fe uptake by the plants, and their accumulation in the aerial portion. Our results suggest that HS products potentialize the nutritional effect of the mineral fertilizer, when applied in combination.

Yield response of barley to the application of mineral fertilizers containing major nutrients on Cambisols and Vertisols in Ethiopia

Increasing barley production in the face of declining soil fertility on smallholder farms is a critical challenge in Ethiopia. The objectives of this study were to (1) determine the optimum rates of nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) fertilizers under a balanced fertilization of other macro- and micronutrients (zinc and boron) and (2) quantify the agronomic efficiency of N and P on Cambisols and Vertisols. The trials were conducted for three consecutive years (2014–2016) on farmers’ fields on 83 sites under rain-fed conditions. On each farm, six rates of N, P, K, and S with a balanced application of the other nutrients were laid out separately in a randomized block design with three replicates. Balanced fertilization resulted in yield increments of 26–59% on Cambisols and 18–74% on Vertisols, as compared with the control (0 N). Application of P increased grain yield from 11% to 30% and from 7% to 14% due to the interaction of P by soil type as compared with the control. The application of K and S, however, had no significant effect on barley yields on either soil type. The highest agronomic efficiency of N (AEN) was obtained from 46 kg N ha−1, with AEN increasing by 117% on Cambisols and 33% on Vertisols, as compared with the highest N rate of 230 kg N ha−1. The maximum agronomic efficiency of P (AEP) was recorded with 10 kg P ha−1 on Vertisols, with AEP increasing by 73% on Cambisols and 452% on Vertisols, as compared with the application of 50 kg P ha−1. With balanced application of other nutrients, use of 230 kg N and 20 kg P ha−1 was recommended for tepid sub-moist mid-highlands and Vertisols. For tepid sub-humid mid-highlands, application of 46 kg N and 20 kg P ha−1 with balanced application of other nutrients was recommended. For Cambisols, application of 230 kg N and 40 kg P ha−1 was recommended with balanced application of the other nutrients. Similarly, application of 230 kg N, 40 kg P, and 10 kg S ha−1 was tentatively recommended for cool sub-most mid highlands. However, response to K was inconsistent and therefore a firm recommendation could not be proposed for the study sites. Further research needs to be conducted on more soil types and locations.

Speciation of P in Solid Organic Fertilisers from Digestate and Biowaste

Phosphorus (P) is a finite resource and its reuse in organic fertilisers made from biowaste and manure should therefore be encouraged. The composition of solid organic fertilisers (SOFs) depends on the type of feedstock and processing conditions, and this may affect P speciation and hence P availability. Phosphorus speciation was assessed in eighteen different SOFs produced from biowaste and digestate. Available P was determined in 10 mM CaCl2 extracts at a fixed pH of 5.5 and at a fixed total P concentration in the suspension. P was dominantly present as inorganic P (>80% of total P). There was a strong variation in the Fe content of the SOFs and hence in the fraction of P bound to reactive Fe/Al-oxides (PFe). The fraction of total P soluble at pH 5.5 correlated negatively with PFe pointing to fixation of P by metal salts added during processing, or by soil mineral particles in case garden waste was processed. Therefore, the use of iron salts in processing plants should be avoided. In addition, the presence of P in poorly soluble precipitates lowered the fraction of easily available P. Overall, this study shows that Pt alone is not a good indicator for the agronomic efficiency of SOFs due to large differences in P speciation among SOFs.

Effective use of various forms of nitrogen fertilizers in barley cultivation

The paper aims to assess the use of various forms of nitrogen fertilizers (seedbed dressing and foliar dressing) in barley cultivation in the steppe and forest-steppe zones of the Omsk region. The research objects were barley, nitrogen fertilizers, ordinary steppe chernozem, forest-steppe meadow chernozem. Variety – Sasha. The most agronomic efficiency in the steppe zone, 5.52 kg of grain derived from 1 kg of fertilizer nitrogen, was yielded in response to the use of N30 in the form of ammonium nitrate and urea during sowing. N60 (seedbed dressing + foliar fertilizing) resulted in a reimbursement of 1 kg of fertilizer active agent in the maximum amount of 4.44 kg (ammonium nitrate + urea, ammonium nitrate + UAN). The greatest reimbursement in the forest-steppe zone, 11.11 kg of grain from 1 kg of fertilizer nitrogen, resulted from the use of N30 in the form of ammonium nitrate and UAN during sowing. N60 (seedbed dressing + foliar dressing) resulted in a reimbursement of 1 kg of active agent in the maximum amount of 11.11 kg of barley (ammonium nitrate + urea). The richest harvest of barley was taken in following seedbed dressing and supplementary fertilizing applied together during the growing season in a total dose of 60 kg/ha. In this case, the yield did not reliably depend on the forms of nitrogen fertilizers used; a greater effect resulted from nitrogen fertilizers in the forest-steppe zone.