Corn is one of the important food crops in the world, in order to pursue high yield and high efficiency, the input of chemical fertilizer has been continuously increased, which has led to the decline of fertilizer utilization rate, environmental pollution and other problems, and the slow-release fertilizer has attracted much attention because of its nutrient characteristics, but the high price limits its wide application;On the other hand, long-term rotary tillage will lead to the shallowness of the soil tillage layer and the increase of the bulk density of the deep soil, and subsoiling can effectively break the bottom layer of the soil plough and reduce the bulk density of the soil. Therefore, in this study, Qiangsheng 388 was used as the experimental material, and under rotary tillage (R) and rotary tillage + subsoiling (R+S), CK (no fertilization), U (100% nitrogen fertilizer), S (100% slow-release fertilizer) and different UNS ratios (nitrogen fertilizer and slow-release fertilizer) were used for two years in field experiments to explore the effects of slow-release fertilizer and urea on soil water use efficiency, dry matter accumulation, nitrogen uptake and utilization, operation and yield under the two tillage methods. The results showed that compared with CK, U and S, UNS significantly improved water use efficiency, dry matter accumulation, nitrogen uptake, operation and yield. Among them, UNS2 (the ratio of S and U was 7:3) was the best. In 2022, R UNS2 had the best water use efficiency, dry matter accumulation, nitrogen uptake, operation and yield, which were 5.05%, 2.0%, 3.88%, 6.18% and 4.06% higher than those of R + S UNS2, respectively. In 2023, R + S UNS2 had the best treatment, which was 1.98%, 2.52%, 1.85%, 2.60% and 2.20% higher than that of R UNS2, respectively. R + S tillage can effectively improve maize yield, nitrogen uptake and utilization, water use and dry matter accumulation; Nitrogen application treatment UNS2 treatment was the best. In summary, R + S UNS2 is the best coordination strategy.

The aim of this study was to explore the characteristics of the combined application of organic fertilizer and inorganic fertilizer using different tillage methods to delay the senescence of maize leaves. The yield and activities of GDH, CAT, APX, GR, and GSH enzymes in maize leaves were measured at different growth stages by using two tillage methods, three organic and inorganic combined applications (P₁, P₂, and P₃), and four control treatments. (1) During the growth period, the R + S and R treatments were P₁ treatments, with the highest enzyme activities noted for GDH, CAT, APX, GR, and GSH, which were 36.79–103.22% higher than those of CK. (2) The average yield of all R + S treatments was higher than that of R treatments, and the average yield of P1 treatment was the highest under R + S, which was 13,663.79 kg hm⁻², which was 6.39%, 7.90%, and 14.67% higher than that of P₂, P₃, and CK, respectively, which was lower than that of R. The yield of P₁ treatment was 2.53% higher. (3) There was a significant positive correlation between APX activity, CAT activity, GR activity, GDH activity, GSH activity, grain number per ear, ear length, and 100-grain weight of maize leaves at the grain filling stage, and a significant negative correlation between bald tip length and yield. The treatment details had the strongest enzyme activity and the highest yield when using the rotary tillage + subsoiling (R + S) P₁ method, which was the most suitable tillage method and the best fertilizer ratio combination, which could be demonstrated and popularized in a large area in the dry farming area of spring maize in Shanxi Province.

High-density maize cultivation can enhance yield, but water scarcity on the Loess Plateau may limit this potential. Mulching is a sustainable practice that conserves soil moisture, yet limited studies exist on the combined effects of planting densities and mulching types on maize performance in this region. Over two years, an experiment investigated the effects of mulching (no mulching (NM), plastic film mulching (PM), and straw mulching (SM)) at various densities (60,000 to 90,000 plants ha⁻¹). The results showed that mulching significantly improved grain yield and other metrics compared to NM. PM and SM enhanced yields notably at 75,000 plants ha⁻¹, while NM was more favorable at 67,500 plants ha⁻¹. Physiological responses varied with density, showing a decreased photosynthesis rate alongside an increased transpiration rate. PM exhibited a 32 and 13% increase in catalase and superoxide dismutase activities, while malondialdehyde content was reduced by 7% compared to NM. The average of both years indicates that PM significantly increased the grain yield, net photosynthesis rate, and chlorophyll content by 5.8, 26.8, and 26.9%, while SM showed a 3, 12, and 12% increase, respectively, compared to NM. In conclusion, the combination of mulching and optimized planting density could enhance maize cultivation in the Loess Plateau.

Quinoa (Chenopodium quinoa Willd.) is gaining recognition as a pseudocereal due to its nutritional attributes and adaptability to challenging conditions and marginal soils. However, understanding the optimal fertilization for quinoa growth remains a challenge. This study investigates the effects of nitrogen fertilization (0, 90, 120, and 150 kg using urea) on quinoa phenology, growth, and photosynthesis in the Loess Plateau region of China, a critical area facing soil erosion and ecological degradation. The results showed that nitrogen fertilization significantly influenced quinoa phenology, prompting early flowering and shorter growth at an optimum rate of 120 kg ha⁻¹. Nitrogen application enhanced growth traits such as plant height, stem diameter, and chlorophyll content, particularly at the heading and flowering stages. Photosynthesis-related parameters, including net photosynthesis rate, transpiration rate, stomatal conductance, and intercellular CO₂ concentration, were affected by nitrogen application, with higher values observed at 120 kg ha⁻¹. Non-photochemical quenching was significantly increased by nitrogen application, indicating the efficient dissipation of excess energy. The study demonstrated a positive correlation between grain yield and growth traits, photosynthesis-related traits, and chlorophyll content. In conclusion, quinoa yield could be significantly improved at the Loess Plateau region under rainfed conditions by an optimal nitrogen fertilizer rate of 120 kg ha⁻¹, which reduces the growth duration while increasing photosynthesis traits.

The objective of this study was to investigate how nitrogen and slow-release fertilizers affect the traits of leaf senescence and quinoa production in order to explore the optimal slow-release fertilizer and nitrogen fertilizer ratios suitable for quinoa production, as well as to provide theoretical references for the planting of quinoa fertilization methods and fertilizer amount. In this experiment, the main local strain Quinoa 77 was selected as the experimental material, and six treatments were set up: CK: no nitrogen fertilizer; T₁: 100% urea (N); T₂: 100% slow-release fertilizer (C); T₃: 5:5 (C₅N₅); T₄: 3:7 (C₃N₇); and T₅: 7:3 (C₇N₃). This was done in order to investigate how various treatments affect the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD); malondialdehyde (MDA) content; and yield of quinoa leaves. The findings revealed the following: (1) As the reproductive period progressed, the activities of CAT, POD, and SOD in quinoa leaves treated differently showed a tendency to increase and subsequently decrease, and they reached the peak value at the early stage of filling. The activity of CAT, POD, and SOD in the T₃ treatment was the highest, and the average activities were 3148.74 U·g⁻¹, 2197.84 U·g⁻¹, and 118.51 U·g⁻¹, respectively, which increased by 78.90%, 101.99%, and 108.14%, respectively, compared with CK. The content of MDA continued to increase with the progress of fertility. The average T₃ treatment was 36.41 nmol·g⁻¹, which was 46.87% lower than that of CK. (2) Out of all the treatments, T₃ had the highest yield with an average of 3829.43 kg·hm⁻², T₅ the second with an average of 3313.52 kg·hm⁻², and T₄ the third with 2847.47 kg·hm⁻², which increased yields by 96.18%, 69.75%, and 45.87%, respectively, compared with CK. (3) Yield was highly significantly and positively correlated with thousand kernel weight; number of grains per spike per plant; and the early filling stages of CAT, POD, and SOD sports, and it had a negative, extremely significant correlation with MDA content. Comprehensive analysis showed that slow-release fertilizer and nitrogen fertilizer can improve the antioxidant enzyme activity of quinoa leaves, inhibit MDA content, improve the physiological characteristics of quinoa, and delay the purpose of leaf senescence, with a better effect of yield and income, of which the T₃ treatment had the high-quality impact of increasing yields and was a more scientific and reasonable fertilization method.

This study aimed to investigate the effects of different planting density and row spacing configurations on maize corn yield, leaf photosynthetic parameters, and senescence characteristics; to reveal the purpose of the physiological mechanism of row density interaction regulatsving maize yield; and to clarify the optimal planting combinations for optimizing population structure, delaying leaf senescence, and improving light energy utilization efficiency. In doing so, this study provides a theoretical basis and technical guidance for increasing corn yield, the sustainable development of the maize industry, and improved yield production in Shanxi Province. An experiment was conducted with a two-factor randomized block design, with three planting densities of 60,000 plants/hm² (D1), 67,500 plants/hm² (D2), and 75,000 plants/hm² (D3) in the main area and four-row spacings of 40 + 40 cm, 40 + 80 cm, 50 + 50 cm, and 80 + 80 cm in the secondary area. The maize kernel yield, leaf photosynthetic parameters, malondialdehyde content, and anti-aging key enzyme activities were measured in 2023 and 2024. The results show that with the increase in planting density, the net photosynthetic rate of maize leaves gradually decreased, and the transpiration rate gradually increased. At the same time, too high or too low density will accelerate the aging of maize leaves, which is manifested by the increase in MDA (malondialdehyde) content and the decrease in SOD (superoxide dismutase) and CAT (catalase) activities. The best row spacing configuration performance is 40 + 80 cm, which is conducive to the ventilation and light transmission of maize plants, improves the efficiency of light energy utilization, slows down the aging of plant leaves, and thus promotes maize growth, development, and yield enhancement. The interaction effect between two intercropping maize factors significantly affects corn yield, with a medium density of 67,500, where 6000 is the most effective. Thus, 67,500 plants/hm² combined with a row spacing of 40 + 80 cm significantly increases corn yield. This combination obtained the highest net photosynthesis, SOD, and CAT of 24.33 µmol·m⁻²·s⁻¹, 32.54 U·mg⁻¹ and 1038.99 U·g⁻¹, and the lowest transpiration rate and MDA content of 3.47 mmo·m⁻²·s⁻¹ and 108.95 µmo·L⁻¹, resulting in the highest maize yield of 13,916.46 kg/hm². In summary, a density of 67,500 plants/hm² and 40 + 80 cm row spacing is the best combination, improving light energy utilization efficiency, delaying the leaf senescence process, and increasing the yield, which can provide a theoretical reference for the planting pattern of maize in Shanxi Province.