Rice cultivation consumes more than half of the planet’s 70% freshwater supply used in agricultural production. Competing water uses and climate change globally are putting more pressure on the limited water resources. Therefore, water-saving irrigation (WSI) is recommended for rice production in water scares areas. The impact of WSI techniques on direct-seeding rice production and greenhouse gas emissions in North China is becoming increasingly important in the era of climate change. Therefore, we conducted a two-year field experiment on directly seeded rice to assess the impact of traditional flooding irrigation (CK) and three water saving irrigation (WSI) methods, including drip irrigation with an irrigation amount of 50 mm (DI₁) and 35 mm (DI₂) at each watering time and furrow wetting irrigation (FWI), on rice yield and greenhouse emissions. Generally, the WSI techniques decreased the number of rice panicles per m⁻², spikelet per panicle, 1000-grain weight and rice yield compared to CK. Rice yield and yield components of (DI₁) were significantly higher than (DI₂). The adoption of either (DI₁) or (FWI) showed insignificant variation in terms of rice yield and its yield components measured except for 1000-grain weight. The water productivity was 88.9, 16.4 and 11.4% higher in the FWI plot than the CK, DI₁ and DI₂ plots, respectively. The WSI decreased cumulative CH₄ emission significantly by 73.0, 84.7 and 64.4% in DI₁, DI₂ and FWI, respectively, in comparison with CK. The usage of DI₂ triggered 1.4 and 2.0-fold more cumulative N₂O emission compared to DI₁ and FWI, respectively. Area-scaled emission among the water-saving irrigation methods showed no significance. The yield-scaled emission in DI₁ and DI₂ and FWI were 101, 67.5 and 102%, respectively, significantly lower than CK. The adoption of FWI produced an acceptable rice yield with the lowest yield-scaled emission and highest water productivity among the irrigation practices. Our experiment demonstrates that dry direct-seeding with furrow irrigation can impact triple-wins of sustainable rice yield, high water-use efficiency and low GHG emissions in North China.

Screening for cultivars with low Cd in edible organs but high Cd accumulation in non-edible organs represents a sustainable strategy for “producing while remediating”. However, the potential of potato cultivars to achieve this dual goal in high-geogenic-Cd karst areas remains unclear. A field experiment was performed to investigate biomass, Cd concentration, bioconcentration factor (BCF), translocation factor (TF) and Cd removal amount (R) in various organs of 26 potato cultivars, which were then classified into different Cd risk types. The results showed that in soils with 2.05–2.98 mg·kg⁻¹ Cd, fresh tuber Cd concentrations ranged from 0.021 to 0.132 mg·kg⁻¹, with nearly 90% of tubers complying with FAO/WHO and Chinese food safety standards. Cd levels in stems, leaves and roots were 1–2 orders of magnitude higher than in tubers, supporting potato as a suitable staple for safe production in such regions. BCF followed the order stem and leaf > root > tuber, while TF followed the order root to stem and leaf > stem and leaf to tuber. Tuber Cd was jointly controlled by Cd uptake, translocation and biomass dilution, with TFstem and leaf–tuber as a key predictor. Annual Cd removal by whole plants ranged from 1082.99 to 7283.64 mg·hm⁻². Principal component analysis classified the cultivars into four types: edible-safe, safe remediation, risky remediation and high-risk types. Notably, cultivars V2, V6, V9, V13, and V18 had tuber Cd concentrations below 50% of the permissible limit, while V16, V8, and V25 achieved >5000 mg·hm⁻² Cd removal without exceeding safety limits. These findings support the dual goal of safe potato production and in situ Cd remediation in high-background karst regions by selecting cultivars with low Cd accumulation in tubers but high Cd accumulation in non-edible organs.

Balancing high rice yield with reduced nitrogen input is a critical challenge for sustainable agriculture. While activated water irrigation shows potential for improving crop performance, its efficacy in synergy with nitrogen management, particularly for enhancing nitrogen use efficiency (NUE), remain largely unexplored. Here, we conducted a pot experiment to evaluate the effects of activated water (i.e. aerated water (AW) and magnetized water (MW)) irrigation, compared to tap water (TW), on rice performance across three nitrogen application rates (low, medium, high). Our findings revealed that activated water, particularly AW, significantly accelerated seed germination and improved seedling establishment. At low and medium nitrogen levels, AW and MW irrigation stimulated significant root tip numbers by a 20.6-32.5% and 13.8-28.7%, respectively. These improvements in root architecture were associated with enhanced nitrogen uptake and higher leaf photosynthetic performance. As a result, AW and MW increased grain yield by 8.2-13.6% and 2.5-8.9%, and elevated NUE by 26.2-32.0% and 14.4-15.7%, respectively, under reduced nitrogen conditions. Conversely, no significant improvements were observed at the high nitrogen level, highlighting that activated water is most effective in nitrogen limited conditions. Given that aerated water demonstrated superior performance, our study suggests that its integration with reduced nitrogen fertilization may offer a potent strategy for achieving environmentally sustainable rice production.

Traditional intercropping systems represent an economically feasible and sustainable strategy for the safe utilization of cadmium (Cd) contaminated farmland. To assess the safe production potential of a maize potato intercropping system in high-heological-Cd background agricultural areas, four planting patterns were set up in the Chongqing karst area, China: maize monoculture (T1), maize–potato intercropping with a 1:1 row ratio (T2), maize–potato intercropping with a 2:2 row ratio (T3), and potato monoculture (T4). We systematically compared soil pH, total Cd, and available Cd across the different planting patterns. Cd concentrations were determined in multiple organs of the two crops: roots, stems, nodes, leaves, husks, cobs, and grains for maize; and roots, stems, leaves, and tubers for potato. Furthermore, Cd bioconcentration factors (BCF), translocation factors (TF), dietary health risks posed by edible organs, and economic benefits under each cropping system were analyzed. The results revealed that: (1) Maize and potato cultivation modified the microenvironment of the soil surrounding the roots. Total and available Cd concentrations in the soil surrounding potato roots were lower than those in the soil surrounding maize roots, although the difference was not significant (p < 0.05). (2) Compared with potato monoculture, 1:1 and 2:2 row ratios of maize–potato intercropping significantly reduced Cd concentrations in fresh potato tubers by 38.81% and 38.01%, respectively; tuber Cd concentrations complied with the national food safety limit. (3) Marked interspecific differences were observed in Cd accumulation and translocation traits between maize and potato. The bioconcentration factor (BCF) of all maize organs was below 1, and Cd concentration and accumulation capacity exhibited a decreasing gradient trend following the order: roots > leaves > nodes > husks ≈ stems > cobs > grains. For potato, the BCF values of roots, stems, leaves, and tubers were all greater than 1, and their Cd accumulation capacities were 9.13-, 67.33-, 20.84-, and 37.67-fold higher than the respective organs of maize, respectively. (4) Based on health risk assessment and economic benefit evaluation, the two maize potato intercropping systems (T2 and T3) achieved substantially higher combined economic returns than maize monoculture (T1), while presenting markedly lower dietary health risks than potato monoculture (T4). This case study validates the hypothesis that maize–potato intercropping alters cadmium translocation and distribution responses within the soil–crop system, and demonstrates its potential to improve farmland economic benefits while guaranteeing agricultural product safety. Consequently, these intercropping patterns represent a promising strategy for promoting safe and green production on High-Geological-Cd background farmland.