Organic fertilizer application and Mg fertilizer promote banana yield and quality in an Udic Ferralsol

Effects of Modified Biochar on Growth, Yield, and Quality of Brassica chinensis L. in Cadmium Contaminated Soils

Cadmium (Cd) pollution in farmland soil leads to excessive Cd in vegetables, which can be transferred to humans through the food chain, posing a significant threat to human health, and requires urgent measures to combat it. Modified biochar may have the potential to remediate Cd pollution in farmland soils. In this experiment, bulk biochar (YC) derived from reed straw or modified biochar by ball milling (Q) either alone or combined with a combination of several passivation agents {potassium hydroxide (K), attapulgite (A), calcium magnesium phosphate fertilizer (M), and polyacrylamide (P)} was applied to soils polluted with Cd, to investigate the growth, yield, and quality of pakchoi (Brassica chinensis L.). The results showed that bulk biochar (YC) provided pakchoi with plenty of nitrogen, phosphorus, and potassium, while passivation agents enhance macronutrient accumulation. Compared to YC, modified biochar improved pakchoi yields and nutritional quality. Among them, concentrations of nitrates in pakchoi significantly decreased by 51.8% and 51.0%, while vitamin C levels increased by 29.6% and 19.0%, respectively, in QKAMP and QKAM treatments. The contents of Cd in pakchoi significantly decreased by 21.6% and 18.6%, respectively, in QKAMP and QKAM treatments. The implementation of QKAMP led to the cadmium contents in edible vegetables being lower than the maximum stipulated content as defined by the national standard, but QKAM failed to accomplish it. In conclusion, QKAMP effectively reduced the bioavailability of Cd in the middle to slightly Cd-polluted alkaline soils, making it a suitable soil amendment to improve the yield and quality and mitigate Cd accumulation in vegetables.

Reduced Fertilization and Magnesium Supplementation: Modulating Fruit Quality in Honey Pomelo (Citrus maxima (Burm.) Merr.)

The excessive use of chemical fertilizers in the Guanxi honey pomelo production area has led to severe soil acidification and magnesium (Mg) deficiency, adversely affecting pomelo fruit quality. To address this issue, an integrated nutrient optimization model crucial for ensuring the sustainable and environmentally friendly development of the Guanxi honey pomelo industry has been explored. In a three-year experiment, two fertilizer treatments were implemented: a farmer fertilizer practice (FP) and an NPK reduction plus foliar Mg fertilizer (OPT + fMg). We investigated the impact of this integrated optimized fertilization measure on pomelo fruit quality from three aspects: flavor (sugars and organic acids), nutrition (vitamin C and mineral elements), and antioxidant properties (phenolics, flavonoids, and phytic acid). The results revealed that the OPT + fMg treatment improved fruit flavor by reducing acidity (titratable acid, citric acid, and quinine), while having a minimal impact on sugar components (sucrose, fructose, and glucose). Additionally, the OPT + fMg treatment increased the total phenolics, total flavonoids, and phytic acid in the fruit peel, enhancing its potential antioxidant quality. However, the OPT + fMg treatment reduced the mineral nutrient quality (excluding calcium) in the fruit. As for the fruit developmental period, the OPT + fMg treatment significantly increased the total flavonoid concentration in the peel from the mid-expansion fruit stage, followed by notable increases in phytic acid in the peel during the mid-to-late expansion fruit stage. The total phenolic concentration in the peel significantly rose only during the late fruit development stage. The most pronounced effect was observed on phytic acid in both peel and pulp. The influence of the OPT + fMg treatment on the mineral nutrients (excluding calcium) primarily occurred during the mid-to-late expansion fruit stage. Overall, the OPT + fMg treatment significantly improved the comprehensive nutritional quality of pomelo fruit, providing valuable insights for scientifically reducing fertilizer application while enhancing fruit quality.

Optimal phosphorus management strategies to enhance crop productivity and soil phosphorus fertility in rapeseed-rice rotation

Optimal phosphorus (P) managements can improve the crop yield without reducing soil P supply capacity over the long term. In this study, the rapeseed-rice rotation experiments were conducted to evaluate the effect of five optimal P fertilizer managements, including the addition of RA (rooting agents), PSB (phosphate solubilizing bacteria), CMP (calcium and magnesium phosphate fertilizer), DP1 (starter P) and DP2 (foliar fertilizer) with the reduction of 40% (in the 1st rapeseed season) and 75% (in the 2nd rapeseed season) P fertilizers of farmers' fertilizer practice (FFP) on crop productivity and soil P fertility in low and high P fertility soils. Seed yield, P partial factor productivity, and P recovery efficiency of both cultivars, Shengguang168 (SG168) and Zhongshuang 11 (ZS11), were significantly improved under optimal P managements, and the increase of them in low P fertility soil was more than that in high P fertility soil. Total P surplus was lower under optimal P managements than under FFP in both P fertility soils. The increasing amount of crop yields under optimal P managements for both cultivars was equivalent to that of 16.0-38.3 kg P₂O₅ hm^-2 of P fertilizer application, and the order of the optimal P managements was as follows: RA > PSB > CMP > DP1 > DP2. In addition, the grain yield of rotated rice cultivar Longliangyou1212 (LLY1212) without P supply was not reduced in both fertility soils. Compared with low P fertility soil, yields of SG168, ZS11 and LLY1212 in high P fertility soil increased by 28.1%-71.7%, 28.3%-78.9% and 26.2%-47.2% at the same treatment, respectively. In summary, optimal P managements in the rapeseed season could stabilize the crop yield, promote P use efficiency and the capacity of soil P supply in the rapeseed-rice rotation, especially in low P fertility soil.

Bacteria not fungi drive soil chemical quality index in banana plantations with increasing years of organic fertilizer application

BACKGROUND

Maintaining or improving soil chemical quality is critical for sustainable agricultural productivity and environmental safeguards. Organic fertilizer application, a common agricultural practice in banana cultivation, is often associated with greater microbial biomass and activity, which are linked to improvements in soil chemical quality. However, the effect of the duration of organic fertilizer application on soil chemical quality and whether it is microbially driven still needs to be investigated. We collected soil samples from banana plantations consistently applying organic fertilizers for 1 (Y1), 4 (Y4), 7 (Y7) and 10 (Y10) years. Soil chemical quality is expressed as total data set (TDS) and minimum data set (MDS) based on chemical indicators, and soil microorganisms are characterized by phospholipid fatty acid (PLFA).

RESULTS

Based on TDS and MDS, the soil chemical quality indices in Y7 and Y10 treatments were significantly higher than that in Y1 and Y4 treatments. Soil total PLFA concentrations and the proportional abundance of fungi and arbuscular mycorrhizal fungi increased with prolonged banana cultivation. Total PLFA concentrations were significantly positive correlation with the soil chemical quality index. Soil gram-positive bacteria (G+), bacteria, protozoa and ratio of G+ to gram-negative bacteria (G-) were major drivers of soil chemical quality.

CONCLUSION

The organic fertilizer application can significantly improve soil chemical quality, which is regulated by soil bacteria. Regular application of organic fertilizers is important in promoting soil quality and soil biological properties need to be incorporated into the assessment of soil health in banana plantations. © 2022 Society of Chemical Industry.

Effect of Various Mulch Materials on Chemical Properties of Soil, Leaves and Shoot Characteristics in Dendrocalamus Latiflorus Munro Forests

The effectiveness of mulch treatments on soil quality as well as on the yield and growth rates of bamboo are major considerations and require further attention. The present work was aimed at assessing the impacts of three different mulch materials on soil available nutrients, biochemical traits, and growth patterns of Dendrocalamus latiflorus Munro. We found that relative to the control (CK), bamboo leaves (MB) and organic fertilizers (MF) treatments significantly (P < 0.05) increased the number of bamboo shoots (47.5 and 22.7%) and yield (21.4 and 9.1%), respectively. We observed that under MB and MF treatments, the concentrations of soil available nutrients (nitrogen, phosphorus, and potassium) increased and played a key role in the differences in chlorophyll, leaf carbohydrate contents (soluble sugar and starch) and were essential to promote bamboo shoot development. Furthermore, we infer from principal component analysis (PCA), that both MB and MF appear to be a better choice than rice husks (MR) to improve nutrient availability, biochemical traits of the leaves, and increased bamboo shoot productivity. Consequently, we suggest using organic fertilizers and bamboo leaves as mulch materials are effective for soil conservation to attain high-quality bamboo production.

Effects of Organic Fertilizer Mixed with Food Waste Dry Powder on the Growth of Chinese Cabbage Seedlings

Food waste is a common global threat to the environment, agriculture, and society. In the present study, we used 30% food waste, mixed with 70% bio-fertilizers, and evaluated their ability to affect the growth of Chinese cabbage. The experiment was conducted using different concentrations of food waste to investigate their effect on Chinese cabbage growth, chlorophyll content, and mineral content. Leaf length, root length, and fresh and dry weight were significantly increased in plants treated with control fertilizer (CF) and fertilizer mixed with food waste (MF). However, high concentrations of food waste decreased the growth and biomass of Chinese cabbage due to salt content. Furthermore, higher chlorophyll content, transpiration efficiency, and photosynthetic rate were observed in CF- and MF-treated plants, while higher chlorophyll fluorescence was observed in the MF × 2 and MF × 6 treatments. Inductively coupled plasm mass spectrometry (ICP-MS) results showed an increase in potassium (K), calcium (Ca), phosphorous (P), and magnesium (Mg) contents in the MF and MF × 2 treatments, while higher sodium (Na) content was observed in the MF × 4 and MF × 6 treatments due to the high salt content found in food waste. The analysis of abscisic acid (ABA) showed that increasing amounts of food waste increase the endogenous ABA content, compromising the survival of plants. In conclusion, optimal amounts of food waste—up to MF and MF × 2—increase plant growth and provide an ecofriendly approach to be employed in the agriculture production system.

An Overview of the Practices and Management Methods for Enhancing Seed Production in Conifer Plantations for Commercial Use

Flowering, the beginning of the reproductive growth, is a significant stage in the growth and development of plants. Conifers are economically and ecologically important, characterized by straight trunks and a good wood quality and, thus, conifer plantations are widely distributed around the world. In addition, conifer species have a good tolerance to biotic and abiotic stress, and a stronger survival ability. Seeds of some conifer species, such as Pinus koraiensis, are rich in vitamins, amino acids, mineral elements and other nutrients, which are used for food and medicine. Although conifers are the largest (giant sequoia) and oldest living plants (bristlecone pine), their growth cycle is relatively long, and the seed yield is unstable. In the present work, we reviewed selected literature and provide a comprehensive overview on the most influential factors and on the methods and techniques that can be adopted in order to improve flowering and seed production in conifers species. The review revealed that flowering and seed yields in conifers are affected by a variety of factors, such as pollen, temperature, light, water availability, nutrients, etc., and a number of management techniques, including topping off, pruning, fertilization, hormone treatment, supplementary pollination, etc. has been developed for improving cone yields. Furthermore, several flowering-related genes (FT, Flowering locus T and MADS-box, MCMI, AGAMOUS, DEFICIENCES and SRF) that play a crucial role in flowering in coniferous trees were identified. The results of this study can be useful for forest managers and for enhancing seed yields in conifer plantations for commercial use.

Increased Organic Fertilizer and Reduced Chemical Fertilizer Increased Fungal Diversity and the Abundance of Beneficial Fungi on the Grape Berry Surface in Arid Areas

Fertilizer practices can significantly impact the fruit quality and microbial diversity of the orchards. The fungi on the surface of fruits are essential for fruit storability and safety. However, it is not clear whether fertilization affects the fungal diversity and community structure on the surface of grape berries. Here, grape quality and the fungal diversity on the surface of grapes harvested from three fertilizer treatments were analyzed shortly after grape picking (T0) and following 8 days of storage (T1). The study involved three treatments: (1) common chemical fertilizer for 2 years (CH); (2) increased organic fertilizer and reduced chemical fertilizer for 1 year (A.O); and (3) increased organic fertilizer and reduced chemical fertilizer for 2 years (B.O). The application of increased organic fertilizer and reduced chemical fertilizer increased the soluble solids content (SSC) of the grape berries and decreased the pH of the grape juice. A total of 827,947 high-quality fungal sequences were recovered and assigned to 527 operational taxonomic units. Members of the Ascomycota phylum were dominant in all samples and accounted for 94.41% of the total number of detected sequences, followed by the Basidiomycota (5.05%), and unidentified fungi (0.54%). Alpha and beta diversity analyses revealed significantly different fungal populations in the three fertilizer treatments over the two time periods. The fungal diversity and richness on the grape berry surface in the B.O and A.O treatments were higher than those in the CH treatment. Among the detected fungi, the B.O treatments were mainly Pichia, Aureobasidium, and Candida genera, while the CH treatments were Botrytis, Aspergillus, and Penicillium. Moreover, significant differences were revealed between the two assessment times (T0 and T1). The samples from the T0 timepoint had higher fungal richness and diversity than the samples from T1 timepoint. Increasing organic fertilizer usage in grape management could improve grape quality and went on to increase the fungal diversity, as well as the relative abundance (RA) of beneficial fungi on grape berry surfaces. The correlation analysis suggested that the pH of the grape juice was significantly negatively correlated with fungal diversity parameters.