Response of Soil Temperature, Moisture, and Spring Maize (Zea mays L.) Root/Shoot Growth to Different Mulching Materials in Semi-Arid Areas of Northwest China

Forecasting Brassica napus production under climate change with a mechanistic species distribution model

Brassica napus, a versatile crop with significant socioeconomic importance, serves as a valuable source of nutrition for humans and animals while also being utilized in biodiesel production. The expansion potential of B. napus is profoundly influenced by climatic variations, yet there remains a scarcity of studies investigating the correlation between climatic factors and its distribution. This research employs CLIMEX to identify the current and future ecological niches of B. napus under the RCP 8.5 emission scenario, utilizing the Access 1.0 and CNRM-CM5 models for the time frame of 2040-2059. Additionally, a sensitivity analysis of parameters was conducted to determine the primary climatic factors affecting B. napus distribution and model responsiveness. The simulated outcomes demonstrate a satisfactory alignment with the known current distribution of B. napus, with 98% of occurrence records classified as having medium to high climatic suitability. However, the species displays high sensitivity to thermal parameters, thereby suggesting that temperature increases could trigger shifts in suitable and unsuitable areas for B. napus, impacting regions such as Canada, China, Brazil, and the United States.

Pyrolytic biochar from plastic film waste addition on farmland for maize growth improvement: Process and effect study

Pyrolyzing and returning to farmland is one of the potential methods for farmland plastic film waste. This study explored both pyrolyzation and activation optimum conditions of a mixture of plastic film (polyethylene) and maize straw (MPS) in a 1:5 ratio to produce MPS-char, investigated the action of the char on the maize seedling stage (for 30 days). The results showed that the char promoted the root to be more advanced than aboveground part, therefore, this study experimentally clarified the role MPS-char played when added to the soil. The functional groups of the char were varied by the participation of polyethylene. Carbon-based groups were observed, such as carbonyl or carboxyl groups, which could constitute an NH₄⁺ absorption release system to increase the existence of urea in soil, therefore the average nitrogen concentration was improved by 16.18 %. However, the shallow soil temperature increased by 2.03 °C, and the deep soil temperature slightly decreased with the effect of MPS-char. While, the soil moisture content was slightly reduced in the second half of the experiment, and the soil oxygen content increased by 7.64 % throughout the whole experiment. Overall, returning MPS-char to farmland showed a positive effect on maize growth, which was caused by the variation of both chemical and physical properties. This variation provides opportunities for further promotion of rhizosphere development.

Response of the Fate of In-Season Fertilizer Nitrogen to Plastic Mulching in Rainfed Maize Croplands of the Loess Plateau

As plastic mulching is widely used for maize production on Loess Plateau, study of the fate of fertilizer nitrogen (N) in rain-fed croplands is of great significance. Field experiments were conducted during 2015–2016 at a typical dry-land farm on the Loess Plateau, China. The stable isotope tracer technique was applied to analyze the effects of plastic mulching on the maize crop yield, N content in the grain, and mechanism of N uptake and utilization in maize plants with plastic mulch (PM) and without plastic mulch (CK) on the Loess Plateau. Maize yield, aboveground dry matter, grain N concentration, and N uptake in aboveground biomass for PM significantly increased, in addition to fertilizer nitrogen recovery and nitrogen production efficiency. Compared to CK, PM improved the total N uptake from the soil in the aboveground biomass by 16.39 and 27.75 kg ha⁻¹ and fertilizer nitrogen recovery by 10.89 and 22.02 kg ha⁻¹, respectively. Furthermore, PM increased in-season fertilizer N retention in the soil by 11.9–24.8 kg ha⁻¹, and the uncountable fertilizer N decreased by approximately 33.8 kg ha⁻¹ on average. In conclusion, PM simultaneously improved the maize yield and N utilization, which provides a scientific basis for nitrogen management in maize croplands.

Stover return and nitrogen application affect soil organic carbon and nitrogen in a double-season maize field

Cultivation techniques have an important influence on grain yield of maize. This experiment investigated the effect of stover return (SR) and different nitrogen (N) application rate on soil organic carbon (SOC) composition, soil nutrient and maize yield. Different nitrogen application rate 100 (N100), 150 (N150), 200 (N200), 250 (N250) or 300 (N300) kg ha^-1 applied to the maize field with stover return and without stover return traditional planting (TP) method. Nitrogen application rate and stover return affected the SOC, labile organic carbon (LOC), microbial biomass (MBC), NO₃ ^- -N, NH₄ ⁺ -N and maize yield. Soil N, soil carbon content and maize yield of SR were all higher than TP. The SOC content of SR and TP were 9.67 and 9.19 g kg^-1 , respectively. Nitrogen application was significantly and positively correlated with soil MBC, LOC, SOC, NO₃ ^- -N, NH₄ ⁺ -N and yield. The maximum values of SOC composition, soil nutrients and maize yield were reached at SR with 250 kg ha^-1 . Stover return with application of N 250 kg ha^-1 significantly increased the growth attribute and maize yield in subtropical region compared with traditional planting.

Cover cropping and its biomass incorporation: Not enough to compensate the negative impact of plastic film mulching on global warming

Plastic film mulching (FM) became a general practice to enhance crop productivity and its net primary production (NPP), but it can increase greenhouse gas (GHG) emissions. The proper addition of organic amendments might effectively decrease the impact of FM on global warming. To evaluate the feasibility of biomass addition on decreasing this negative influence, cover crop biomass as a green manure was incorporated with different recycling levels (0-100% of aboveground biomass) under FM and no-mulching. The net global warming potential (GWP) which integrated with soil C stock change and GHG (N₂O and CH₄) fluxes with CO₂-equivalent was evaluated during maize cultivation. Under the same biomass incorporation, FM significantly enhanced the grain productivity and NPP of maize by 22-61 and 18-58% over no-mulching, respectively. In contrast, FM also highly increased the respired C loss, which was 11-95% higher than NPP increase, over no-mulching. Irrespective with biomass recycling ratio and mulching system, negative NECB which indicates the decrease of soil C stock was observed, mainly due to big harvest removal. FM decreased more soil C stock by 57-158% over no-mulching, but its C stock was clearly increased with increasing biomass addition. FM significantly increased total N₂O and CH₄ fluxes by 4-61 and 140-600% over no-mulching, respectively. Soil C stock changes mainly decided net GWP scale, but N₂O and CH₄ fluxes negligibly influenced. As a result, FM highly increased net GWP over no-mulching, while this net GWP was clearly decreased with increasing biomass application. However, cover cropping, and its biomass recycling was not enough to compensate the negative impact of FM on global warming. Therefore, more biomass incorporation might be essential to compensate this negative effect of FM.

Getting to the Root of Belowground High Temperature Responses in Plants

The environment is continuously challenging plants. As a response, plants use various coping strategies, such as adaptation of their growth. Thermomorphogenesis is a specific growth adaptation that promotes organ growth in response to moderately high temperature. This would eventually enable plants to cool down by dissipating the heat. Although well understood for shoot organs, the thermomorphogenesis response in roots only recently obtained increasing research attention. Accordingly, in the last few years, the hormonal responses and underlying molecular players important for root thermomorphogenesis were revealed. Other responses triggered by high temperature in the root encompass modifications of overall root architecture and interactions with the soil environment, with consequences on the whole plant. Here, we review the scientific knowledge and highlight the current understanding on roots responding to moderately high and extreme temperature.

Influence of plastic film mulch with biochar application on crop yield, evapotranspiration, and water use efficiency in northern China: A meta-analysis

Background

China is the leading consumer of plastic film worldwide. Plastic film mulched ridge-furrow is one of the most widely adopted agronomic and field management practices in rain-fed agriculture in dry-land areas of China. The efficiency of plastic film mulching as a viable method to decrease evapotranspiration (ET), increase crop yields, and water use efficiency (WUE), has been demonstrated extensively by earlier studies.

Methods

A comprehensive evaluation of how co-application of plastic-film mulch and biochar in different agro-environments under varying climatic conditions influence ET, crop yield, WUE, and soil microbial activity were assessed. We performed a meta-analysis using the PRISMA guideline to assess the effect of plastic-film mulched ridge-furrow and biochar on ET, yield, and WUE of wheat (Triticum aestivum L.), potato (Solanum tuberosum L.), and maize (Zea mays L.) in northern China.

Results

The use of plastic film increased average yields of wheat (75.7%), potato (20.2%), and maize (12.9%) in Gansu, Ningxia, Shaanxi, and Shanxi provinces, respectively due to the reduction in ET by 12.8% in Gansu, 0.5% in Ningxia, and 4.1% in Shanxi, but increased in Shaanxi by 0.5% compared to no-mulching. These changes may be attributed to the effect of plastic film mulch application which simultaneously increased WUE by 68.5% in Gansu, 23.9% in Ningxia, 16.2% in Shaanxi, and 12.8% in Shanxi, respectively. Compared to flat planting without mulching, in three years, the yield of maize increased with the co-application of plastic film and biochar by 22.86% in the Shanxi and Shaanxi regions.

Conclusion

Our analysis revealed co-application of plastic film with biochar is integral for improving soil and water conservation in rain-fed agriculture and as an integrated practice to avert drought while simultaneously mitigating runoff and erosion.