Metal Accumulation Properties of Eight Traditionally Utilized Nutritional Plants and Their Potential as Suitable Crops for Cultivation on Acidic Soils of the Northern Province Uíge, Angola

High metal contents of acidic soils from sub-Saharan Africa often prevent the cultivation of crops and lead to a low livestock yield. The carbohydrate rich diet of the Angolan population is low in minerals and vitamins, resulting in various deficiency syndromes and a high child mortality rate. Eight traditionally utilized plants (Anisophyllea quangensis, Annona stenophylla subsp. cuneata, Canarium schweinfurthii, Eugenia malangensis, Landolphia lanceolata, Raphionacme madiensis, Tristemma mauritianum, Vitex madiensis subsp. madiensis) with nutritional value for the Angolan population were analyzed for their soil and growing conditions. The species are adapted to the local conditions and can serve as crops for the unfavorable soils of the province Uíge. Chemical and physical characteristics of the uppermost soil (0–5 cm) and in 30 cm depth were analyzed. The plant-available macro-and micronutrients were determined using Mehlich 3 extraction. Data are completed with leaf tissue analyses, examining the uptake of minerals. As aluminum (Al) and manganese (Mn) are plant-available in high amounts, local plants evolved mechanisms dealing with those metals. These Al accumulators with foliar contents above 1000 mg/kg are Anisophyllea quangensis (7884 mg/kg), Landolphia lanceolata (6809 mg/kg), Tristemma mauritianum (4674 mg/kg), and Eugenia malangensis (13,989 mg/kg). All four species bear edible fruits with nutritional potential. The domestication and commercialization of those plants seem to be promising, utilizing local soils without expensive amelioration techniques.

Adaptive Mechanisms Make Lupin a Choice Crop for Acidic Soils Affected by Aluminum Toxicity

Almost half of the world’s agricultural soils are acidic, and most of them present significant levels of aluminum (Al) contamination, with Al3+ as the prevailing phytotoxic species. Lupin is a protein crop that is considered as an optimal alternative to soybean cultivation in cold climates. Lupins establish symbiosis with certain soil bacteria, collectively known as rhizobia, which are capable of fixing atmospheric nitrogen. Moreover, some lupin species, especially white lupin, form cluster roots, bottlebrush-like structures specialized in the mobilization and uptake of nutrients in poor soils. Cluster roots are also induced by Al toxicity. They exude phenolic compounds and organic acids that chelate Al to form non-phytotoxic complexes in the rhizosphere and inside the root cells, where Al complexes are accumulated in the vacuole. Lupins flourish in highly acidic soils where most crops, including other legumes, are unable to grow. Some lupin response mechanisms to Al toxicity are common to other plants, but lupin presents specific tolerance mechanisms, partly as a result of the formation of cluster roots. Al-induced lupin organic acid secretion differs from P-induced secretion, and organic acid transporters functions differ from those in other legumes. Additionally, symbiotic rhizobia can contribute to Al detoxification. After revising the existing knowledge on lupin distinct Al tolerance mechanisms, we conclude that further research is required to elucidate the specific organic acid secretion and Al accumulation mechanisms in this unique legume, but definitely, white lupin arises as a choice crop for cultivation in Al-rich acidic soils in temperate climate regions.

Evaluating Slow Pyrolysis of Parthenium hysterophorus Biochar: Perspectives to Acidic Soil Amelioration and Growth of Selected Wheat (Triticum aestivum) Varieties

Application of biochar on acidic soils may improve soil fertility and crop productivity. This study aimed to explore the relevance of parthenium biochar-induced changes in the physicochemical properties and agronomic performance of the selected wheat varieties in acidic soils. A pot trial was used in determining the effect of slow pyrolysis parthenium biochar on acidic soils and the agronomic performance of wheat varieties. A general linear model (GLM) of multivariate analysis and principal component analysis (PCA) was used to compare functional variation among soil assayed parameters with biochar dosages and years. Biochar-treated acidic soils did not show significant differences in their physical properties. However, a significant incremental trend was observed in the soil moisture content. The biochar-amended acidic soils showed noticeable differences in the soil pH, available phosphorous, and exchangeable bases (Ca, K, and Na) compared to the control. In all soil samples, a decreasing trend in the soil micronutrients was observed with an increase in the biochar amounts. The analysis also unveiled significant changes in root length, root and shoot dry biomass, and plant height of wheat varieties in response to the biochar amendments. The application of 19.5 t/ha and 23 t/ha dosages of biochar gave the maximum changes in the agronomic performance of Kekeba and Ogolcha varieties, while the minimum was obtained in the 26.5 t/ha and the control. Furthermore, PCA axis 1 accounted for 74.34% of the total variance within a higher eigenvector value (10.4076), and most of the soil parameters were positively correlated with CEC (0.29), available phosphorous (0.29), and soil pH (0.28); however, the micronutrients were negatively correlated. In conclusion, Parthenium hysterophorus biochar has the potential to amend acidic soils, and thus, the application of 16.0, 19.5, and 23 t·ha−1 biochar dosages are considered suitable to reduce the soil acidity level and improve the agronomic performance of wheat varieties. However, extensive research will be needed to determine the effects of biochar on soil properties and crop production in field conditions.

Evaluation of phosphate sorption capacity and external phosphorus requirement of some agricultural soils of the southwestern Ethiopian highlands

<span>One of the most soil fertility management problems for crop production on acidic soils of the Ethiopian highlands is phosphorus fixation. The research was executed to assess the P-sorption capacity and to determine the external P requirement of different acidic soils in the Southwestern highlands of Ethiopia. Phosphorus sorption capacity (Kf) and its relation with selected soil characteristics were assessed for some major agricultural soils in the Ethiopian highlands to answer the questions, ‘What are the amount of P-sorption capacity and external P requirement of Nitisols, Luvisols, Alisols, and Andosols in Ethiopia?’. Twelve surface soil samples (at depth of 0-30 cm) were gathered and the P-sorption capacity was estimated. Phosphorus-sorption data were obtained by equilibrating 1 g of the 12 soil samples with 25 ml of KH₂PO₄ in 0.01 M CaCl2, having 0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, and 330 mg P L^-1 for 24 hours. The data were adjusted to the Freundlich adsorption model and the relationship among P-sorption and soil characteristics was established by correlation analysis. Clay content and exchangeable acidity, organic matter, Al₂O₃, and Fe₂O₃ oxides have affected phosphorus-sorption at a significance level of (P &lt; 0.05). Alisols had the highest Kf value (413 mg kg^-1) but Nitisols had the lowest Kf (280 mg kg^-1). The external phosphorus fertilizer requirement of the soils was in the order of 25, 30, 32, and 26 mg P kg^-1 for Nitisols, Luvisols, Alisols, and Andosols sequentially. The Kf varies among different soil types of the study area. The magnitude of the soil’s Kf was affected by the pH of the soil, soil OM content, and oxides of Fe and Al. Therefore, knowledge of the soils’ P retention capacity is highly crucial to determine the correct rate of P </span><span>fertilizer</span><span> for crop production.</span>

The main results of monitoring the fertility of arable soils in the forest-steppe zone of the Central Chernozem Region (on the example of the Belgorod)

The paper analyzes the results of an agrochemical survey for 2010-2019 of arable soils of the Ivnyansky district of the Belgorod region, located in the south-west of the forest-steppe zone of the Central Chernozem region (CDR). It was found that in the soil and climatic conditions of this area for the period from 2010-2014 to 2015-2019. a decrease in the doses of applied mineral fertilizers from 126.6 to 122.8 kg/ha and a simultaneous increase in the doses of organic fertilizers from 18.3 to 23.1 t/ha contributed to an increase in the yield of winter wheat by 28.3%, spring barley - by 22.7%, corn for grain - by 24.7%, sugar beet - by 34.8%, sunflower - by 26.6% and soybeans - by 15.2%. At the same time, the content of mobile forms of phosphorus in soils increased by 29, potassium - by 53, sulfur - by 0.20, copper - by 0.51, manganese - by 3.61, cobalt - by 0.007 mg/kg, organic matter - by 0.25%. As a result of the implementation of measures for chemical reclamation of acidic soils on an area of 29.6 thousand hectares, the proportion of acidic soils decreased from 80.0 to 56.2%. Keywords: RECLAMATION, TRACE ELEMENTS, ORGANIC MATTER, PHOSPHORUS, POTASSIUM, FERTILIZERS, CHERNOZEM, FERTILITY, ACIDITY

The effectiveness of technology packages of 15 biofertilizer formulas to increase soybean productivity on acidic soils

The potentcy of acidic soils for soybean development in Indonesia is quite large. However low of soil fertility and microorganisms population become contrains for achieving high productifity of soybean. The aim of this research is to determine the effectiveness of technology packages for 15 biofertilizers formula to increase soybean productivity in acidic soils. The research was conducted during the end of rainy season in South Kalimantan. The soil use in the study had pH 5.2 and soil Al-saturation 34.2%. The reasearch was arranged in a randomized block design, three replications consisted of 20 treatmens, namely: 1) 0 NPK, 2) 50% NPK, 3) 50% NPK +2 t/ha organic fertilizer 4) 70% NPK, 5) 100% NPK (100 kg urea + 100 kg SP36 + 100 kg KCl/ha), 6) Iletrisoy+ Biovam+Starmix, 7) Iletrosoy Plus, 8) Beyonic, 9 Biotrico, 10) Probio New, 11) RhizoBIOST, 12) Bio-SRF, 13) Biopim, 14) BioMIGE, 15) Biocoat, 16) FajarSOYA, 17) Rhizobion, 18) Agrizone, 19) Rhizoplus, and 20) BISRF. For each biological fertilizer, 50-75% of recommended NPK fertilizers were given at 15 days after planting. The results indicated that combination of Biovam + Iletrisoy + Startmix biofertilizers, Iletrisoy plus, Biotricho, Probio New, Bio Mige, and Fajar SOYA were effective for increasing soybean productivity on acidic soils. These biological fertilizers + 50% recommended NPK + 1.5 t/ha organic fertilizer increases pods number, and soybean productivity more than 10% compared to the recommended NPK fertilizer dosage whic was 1.81 t/ha. Several of these biological fertilizers have good prospects to be developed as bio-fertilizers for soybeans in acidic soils.