Controlled-release urea (CRU) releases nitrogen (N) at the same pace that rice takes it up, which can effectively improve N use efficiency, increase rice yield and improve rice quality.  However, few studies have described the effects of CRU application on the photosynthetic rate and endogenous enzyme activities of rice.  Accordingly, a two-year field trial was conducted with a total of seven treatments: CK, no N fertilizer; BBF, regular blended fertilizer; RBBF, 20% N-reduced regular blended fertilizer; CRF1, 70% CRU+30% regular urea one-time base application; CRF2, 60% CRU+40% regular urea one-time base application; RCRF1, CRF1 treatment with 20% N reduction; and RCRF2, CRF2 treatment with 20% N reduction.  Each treatment was conducted in triplicate.  The results showed that the N recovery efficiency (NRE) of the controlled-release bulk blending fertilizer (CRBBF) treatments was significantly greater over the two years.  There were significant yield increases of 4.1–5.9% under the CRF1 treatment and 5.6–7.6% under the CRF2 treatment compared to the BBF treatment, but the differences between the reduced-N treatments RBBF and RCRF2 were not significant.  Photosynthetic rates under the CRF1 and CRF2 treatments were significantly higher than under the other treatments, and they had significantly greater RuBPCase, RuBisCO, glutamate synthase (GOGAT) and glutamine synthetase (GS) enzyme activities.  Additionally, the soil NH₄⁺-N and NO₃^–-N contents under the CRBBF treatments were significantly higher at the late growth stage of rice, which was more in-line with the fertilizer requirements of rice throughout the reproductive period.  CRBBF also led to some improvement in rice quality.  Compared with the BBF and RBBF treatments, the protein contents under the CRBBF treatments were reduced but the milling, appearance, eating and cooking qualities of the rice were improved.  These results showed that the application of CRBBF can improve the NRE, photosynthetic rate and endogenous enzyme activities of rice, ensuring sufficient N nutrition and photosynthetic material production during rice growth and thereby achieving improved rice yield and quality.

Drought is one of the most important abiotic stresses affecting maize growth and development and therefore resulting in yield loss.  Thus it is essential to understand molecular mechanisms of drought stress responses in maize for drought tolerance improvement.  The root plays a critical role in plants sensing water deficit.  In the present study, two maize inbred lines, H082183, a drought-tolerant line, and Lv28, a drought-sensitive line, were grown in the field and treated with different water conditions (moderate drought, severe drought, and well-watered conditions) during vegetative stage.  The transcriptomes of their roots were investigated by RNA sequencing.  There were 1 428 and 512 drought-responsive genes (DRGs) in Lv28, 688 and 3 363 DRGs in H082183 under moderate drought and severe drought, respectively.  A total of 31 Gene Ontology (GO) terms were significantly over-represented in the two lines, 13 of which were enriched only in the DRGs of H082183.  Based on results of Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis, “plant hormone signal transduction” and “starch and sucrose metabolism” were enriched in both of the two lines, while “phenylpropanoid biosynthesis” was only enriched in H082183.  Further analysis revealed the different expression patterns of genes related to abscisic acid (ABA) signal pathway, trehalose biosynthesis, reactive oxygen scavenging, and transcription factors might contribute to drought tolerance in maize.  Our results contribute to illustrating drought-responsive molecular mechanisms and providing gene resources for maize drought improvement.

Cinnamon essential oil (CEO) and its combination with bamboo leaf flavonoid (BLF) have been shown to exhibit an additive antibacterial effect in vitro, but their functions in broilers were not clear.  An experiment was conducted to investigate the effects of dietary graded levels of CEO and its combination with BLF on the growth performance, immune responses, antioxidative ability, and intestinal morphology and microbiota of broilers fed a corn-soybean meal basal diet.  A total of 576 1-d-old Arbor Acres commercial male broilers were randomly allotted to 9 treatments with 8 replicates of 8 birds each in a completely randomized design.  Birds were fed on a basal corn-soybean meal diet (control, without plant extracts and antibiotics), or the basal diet supplemented with 50 mg of aureomycin kg^–1, 50, 100, 200, 400, or 800 mg  of CEO kg^–1, a combination of 100 mg of CEO and 16.7 mg of BLF kg^–1, or a combination of 200 mg of CEO kg^–1 and 33.3 mg of BLF kg^–1 for 42 d.  Dietary treatment affected (P<0.05) the serum immune globulin M (IgM) contents on d 42, liver malondialdehyde (MDA) contents on d 21, duodenal crypt depth on d 42, relative abundance of Lactobacillus in the cecal contents on d 21, and relative abundances of Escherichia coli and Bifidobacterium in the cecal contents on d 42, but had no effect (P>0.16) on all other measured indices.  The addition of 400 mg of CEO kg^–1 or a combination of 200 mg CEO kg^–1 and 33.3 mg BLF kg^–1 increased (P<0.02) serum IgM contents on d 42.  Dietary supplementation with 100 or 200 mg CEO kg^–1, or 50 mg aureomycin kg^–1 decreased (P<0.003) liver MDA contents on d 21.  In addition, the supplement of 100 mg CEO kg^–1 increased (P<0.002) the Lactobacillus relative abundance in caecum on d 21 and Bifidobacterium relative abundance in caecum on d 42, and decreased (P<0.0001) E. coli relative abundance in caecum on d 42.  The results indicated that dietary supplementation with CEO, an alternative to aureomycin, improved the immune status, antioxidantative ability and cecal microbiota of broilers, and dietary supplementation with the combinations of CEO and BLF did not exhibit further effects.  Dietary supplementation with 100 mg CEO kg^–1 is beneficial for broilers fed a corn-soybean meal basal diet.

Apple occupies a dominant position in fruit production globally, and has become the main income source of local smallholder farmers in Luochuan County in the Loess Plateau area, one of the largest apple production areas in China.  However, the annual productivity of apple orchards in this region remains low and has gradually declined over the years.  The distinction and correlation of production constraints can contribute to the promotion of apple orchard productivity and the development of a sustainable orchard system.  In the present study, survey data from 71 smallholder farmers were analyzed using a yield gap model to distinguish the production constraints and determine their correlation with the yield gap based on the structural equation model (SEM).  The results indicated that the average apple yield in Luochuan County was 29.9 t ha^–1 yr^–1, while the attainable yield (Yatt; the highest yield obtained from the on-farm surveys) was 58.1 t ha^–1 yr^–1.  The average explained and unexplainable yield gaps were 26.3 and 1.87 t ha^–1 yr^–1.  According to the boundary line analysis, crop load, number of sprayings and base fertilizer N were the top three constraints on apple production in 9.8, 7.8 and 7.8% of the plots, respectively.  Among the production constraints, crop load and fruit weight affected apple yield through direct pathways, whereas other constraints influenced apple yield through an indirect pathway based on the SEM, explaining 51% of the yield variance by all the main production constraints.  These results can improve the current understanding of production constraints and contribute to the development of management strategies and policies for improving apple yield.