Wei Gao

Localized phosphorus (P) application stimulates root proliferation in nutrient-rich zones, aligns root growth with soil P distribution, and enhances nutrient uptake efficiency. However, whether localized P supply benefits pitaya remains unclear. In this study, pitaya seedlings were used in a rhizobox experiment with four P treatments: no P (No-P), uniform P (Uniform-P1, 50 mg kg⁻¹), localized P (Local-P1, 50 mg kg⁻¹), and uniform high P (Uniform-P2, 200 mg kg⁻¹). Phosphorus treatments significantly affected shoot growth. Localized P supply produced greater shoot biomass than both uniform and high uniform P. It also increased shoot nitrogen and potassium content but did not significantly affect P content. Localized P application strongly promoted root development. Compared with Uniform-P1, Local-P1 increased root biomass, total root length, root surface area, and root volume by 142.11%, 121.77%, 110.25%, and 100.19%, respectively. Moreover, total root length, root surface area, and root volume were positively correlated with nitrogen and potassium content as well as total biomass. These findings demonstrate that localized P supply improves root morphology, enhances nitrogen and potassium acquisition, and promotes shoot growth in pitaya.

Organic and inorganic nitrogen play important roles in plant nitrogen nutrition. However, how the coapplication of organic and inorganic nitrogen affects root growth, plant nitrogen metabolism, and soil nitrogen content is still unclear. Plant shoot and root growth, nitrogen uptake and metabolism, and soil nitrogen content were studied in maize (Zea mays L.) through pot experiments with different nitrogen treatments, including NH₄⁺ -N (Amm), NO₃⁻ -N (Nit), NH₄⁺ -N + NO₃⁻ -N (Amm + Nit), NH₄⁺ -N + NO₃⁻ -N + glutamate-N (Amm + Nit + Glu), and NH₄⁺ -N + NO₃⁻ -N + glycine-N (Amm + Nit + Gly). The results show that the shoot nitrogen uptake of maize treated with Amm + Nit + Gly was the highest among all the nitrogen treatments. In addition, the coapplication of glycine and inorganic nitrogen increased glutamine synthetase (GS) activity in the maize leaves, promoted nitrogen metabolism levels, and was conducive to the accumulation of amino acids and soluble protein in leaves. Compared with inorganic nitrogen, glycine combined with inorganic nitrogen increased the total root length and root surface area. A correlation analysis showed that total root length and root surface area had a significant positive effect on nitrogen uptake. When ammonium, nitrate, and glycine were applied together, the content of inorganic nitrogen and total nitrogen in soil was higher than that for other inorganic nitrogen treatments. Therefore, we conclude that glycine combined with inorganic nitrogen can increase soil nitrogen content, promote maize root growth, and thus facilitate nitrogen uptake and metabolism.

The large outbreak of banana Fusarium wilt has become a bottleneck limiting the industry’s development, and crop rotation is a cost-effective and essential measure to overcome the obstacles of banana crop monoculture. The present work was carried out to explore the mechanisms of how changes in soil chemical properties and the reestablishment of soil microorganisms in high-incidence soils are affected by crop rotation and plant residue. In this study, pineapple–banana crop rotation and pineapple residue amendment were carried out to alleviate banana Fusarium wilt, and their effects on bacterial and fungal communities were analyzed using the MiSeq Illumina sequencing platform. Both pineapple–banana rotation and residue addition significantly reduced disease incidence. Moreover, pineapple rotation and residue amendment altered the bacterial and fungal community composition. The taxonomic and phylogenetic alpha diversity of bacteria and fungi significantly increased against disease suppression and nutrition competition. The relative abundances of the Burkholderia, Pseudomonas, Elaphocordyceps, Penicillium, and Talaromyces genera were higher, and the number of Fusarium was significantly lower in rotational soil than in banana monoculture soil. Finally, linear models (LM) showed that the Burkholderia and Talaromyces in crop rotation, and Aspergillus in residue amendment had a significantly negative relationship to disease incidence, which plays a key role in Fusarium reduction. To consider the economic benefits and protect the vitality of the soil, this study suggested that pineapple–banana rotation and pineapple residue amendment both could be considered for the sustainable management of banana wilt.