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BackgroundFor achieving long-term sustainability of intensive agricultural practices, it is pivotal to understand belowground functional stability as belowground organisms play essential roles in soil biogeochemical cycling. It is commonly believed that resource availability is critical for controlling the soil biodiversity and belowground organism interactions that ultimately lead to the stabilization or collapse of terrestrial ecosystem functions, but evidence to support this belief is still limited. Here, we leveraged field experiments from the Chinese National Ecosystem Research Network (CERN) and two microcosm experiments mimicking high and low resource conditions to explore how resource availability mediates soil biodiversity and potential multi-trophic interactions to control functional trait stability.ResultsWe found that agricultural practice-induced higher resource availability increased potential cross-trophic interactions over 316% in fields, which in turn had a greater effect on functional trait stability, while low resource availability made the stability more dependent on the potential within trophic interactions and soil biodiversity. This large-scale pattern was confirmed by fine-scale microcosm systems, showing that microcosms with sufficient nutrient supply increase the proportion of potential cross-trophic interactions, which were positively associated with functional stability. Resource-driven belowground biodiversity and multi-trophic interactions ultimately feedback to the stability of plant biomass.ConclusionsOur results indicated the importance of potential multi-trophic interactions in supporting belowground functional trait stability, especially when nutrients are sufficient, and also suggested the ecological benefits of fertilization programs in modern agricultural intensification. Video Abstract.

Background: Patients with DNA mismatch repair‐proficient/microsatellite stable (pMMR/MSS) colorectal cancer (CRC), which accounts for 85% of all CRC cases, display a poor respond to immune checkpoint inhibitors (i.e., anti‐PD‐1 antibodies). pMMR/MSS CRC patients with locally advanced cancers need effective combined therapies. Methods: In this pilot study, we administered six preoperative doses of each 2‐week cycle of the anti‐PD‐1 antibody sintilimab (at a fixed dose of 200 mg), oxaliplatin, and 5‐FU/CF (mFOLFOX6) combined with five doses of bevacizumab (the number of doses was reduced to prevent surgical delays) to patients with cT4NxM0 colon or upper rectal cancers. And radical surgery was performed approximately 2 weeks after the last dose of neoadjuvant therapy. The primary endpoint was a pathologic complete response (pCR). We also evaluated major pathologic response (MPR, ≤10% residual viable tumor), radiological and pathological regression, safety, and tumor mutation burden (TMB), and tumor microenvironment (TME) characteristics. Results: By the cutoff date (September 2023), 22 patients with cT4NxM0 pMMR/MSS colon or upper rectal cancers were enrolled and the median follow‐up was 24.7 months (IQR: 21.1–26.1). All patients underwent R0 surgical resection without treatment‐related surgical delays. pCR occurred in 12 of 22 resected tumors (54.5%) and MPR occurred in 18 of 22 (81.8%) patients. At the cutoff date, all patients were alive, and 21/22 were recurrence‐free. Treatment‐related adverse events of grade 3 or higher occurred in of 2/22 (9.1%) patients. Among the pCR tumors, two were found to harbor POLE mutations. The degree of pathological regression was significantly greater than that of radiological regression (p = 1.35 × 10−8). The number of CD3+/CD4+ cells in the tumor and stroma in pretreated biopsied tissues was markedly lower in pCR tumors than in non‐pCR tumors (p = 0.038 and p = 0.015, respectively). Conclusions: Neoadjuvant sintilimab combined with bevacizumab and mFOLFOX6 was associated with few side effects, did not delay surgery, and led to pCR and non‐pCR in 54.5% and 81.8% of the cases, respectively. Downregulation of CD3/CD4 expression in the tumor and stroma is related to pCR. However, the molecular mechanisms underlying PD‐1 blockade‐enhanced targeted chemotherapy require further investigation. [ABSTRACT FROM AUTHOR]

Soil mineralization, the process of organic to inorganic N which balances the N uptake by crop and N loss to environment, was always quantified by short-term (one day to thirty weeks) incubation experiment. However, the residuary effect of fertilization for N mineralization, especially manure application, is long-term existed, which is important and thought to be shaped by fertilization, soil properties, and climate. Here, we defined and examined dynamic shifts in long-term N mineralization (LT-Nmin) between the first decade and later period after treated with no-fertilizer, conventional fertilizer with/without manure, fertilizer with stover return, in six typical agricultural zones over multiple decades. Soil total N (TN) and available N (AN) increased at rates of 10.1–58.2 mg· kg-1·yr-1 and 1.41–4.13 mg· kg-1·yr-1, respectively, by manure application at five sites, suggesting that manure enhanced both soil N storage and availability. The LT-Nmin rate, defined as slope of the correlation between soil AN and TN indicated that AN increased by 70–81 mg per gram of TN increase, regardless of fertilization. Considering the fertilization period, the LT-Nmin rate with manure application were higher in the first decade (42–181 mg·g-1) than those in later period (33–92 mg·g-1) at all sites. Variance partitioning analysis showed that soil properties contributed 35 % to LT-Nmin in the first decade and increased to 45 % in the later period, while climatic conditions contributed 19 % first, but 8 % in the later period. Structural equation modeling suggested that LT-Nmin was directly affected by annual temperature, with a standardized path coefficient of 0.86 in the first decade and 0.45 in the later period. These results showed that the residual N in soil was mineralized with a high rate in the first decade after fertilization and then slowed down, and the interactions between climate and soil had an enhanced impact on LT- Nmin in later years of fertilization. This context-dependent understanding of interactions between soil properties, N cycling, and climate can thus inform soil management strategies to improve N availability and reduce the N loss to environment. [ABSTRACT FROM AUTHOR]

This study determined N uptake by serrano chilli pepper for two years and evaluated the effects of biochar amendment or organic N (org‐N) fertilizer on N use under a Mediterranean climate. A field experiment was conducted using microplots from 2016 to 2017 in California, USA. Treatments included biochar amendment rates [0 (control), 10, 30 and 50 tons (t) ha−1] biochar, all with 100% inorganic N fertilizer (165 kg N ha−1), and org‐N fertilizer applications at 50%, 75% and 100% of the total available N supply. Pepper yield, vegetative biomass, N uptake, ammonia (NH3) volatilization and changes in soil organic carbon (SOC), and nitrate were determined. Pepper yield was highest in the 50% org‐N and lowest in the 50 t ha−1 biochar treatment during the first year. There were no differences in fruit yield among the organic treatments during the second year, and all were higher than that from the control. The 100% org‐N treatment had less NH3 volatilization than all other treatments during the first year. The two‐year results showed that chilli pepper plants sequestered 4.6‒6.1 kg N to produce one ton fresh pepper fruits. During the first year, the 50% org‐N treatment resulted in the highest N productivity or yield with lowest projected N fertilizer application requirements as compared to other treatments although there were no differences among all treatments in the second year. Thus, a combination of inorganic and org‐N fertilizers can be an effective strategy to improve soil N productivity in long‐term management. [ABSTRACT FROM AUTHOR]

Organic soil amendments can improve soil health but their role in improving N management has not been well quantified. The objectives of this research were to evaluate the influence of biochar and manure compost application on crop yield, N uptake, changes in soil and environmental losses and to use the information to assess the N requirement and project fertilization needs. A field experiment was conducted in California, USA, with processing tomato (Lycopersicon esculentum Mill.) grown first, followed by garlic (Allium sativum). The soil was a sandy loam with a pH of 7.2 and CEC of 9.1 cmol(+) kg−1. Treatments included two biochar products, derived from almond shell or softwood feedstocks, applied at 20 or 40 tonnes (t) ha−1, dairy manure compost at 20 t ha−1, combinations of the manure and the biochar (each at 20 t ha−1), and a control. Although biochar and manure applications improved the surface soil organic C and total N content, no significant effects on crop yield, biomass and N uptake, as well as ammonia volatilization and leaching loss, were observed. The amount of N sequestered by plants ranged from 3.2 to 3.8 and 9.9 to 10.0 kg N Mg−1 to produce fresh tomato fruits and garlic bulbs, respectively. However, about half of the N for tomato and 93% for garlic plants were removed from soil by harvesting. The N sequestered per unit biomass (or yield) production appears a stable parameter, which can be used to reliably project fertilization needs that target high NUE and minimal loss to the environment. [ABSTRACT FROM AUTHOR]