Effect of exogenous application of biogenic silicon sources on growth, yield, and ionic homeostasis of maize (Zea mays L.) crops cultivated in alkaline soil.

Salinity has emerged as a major threat to food security and safety around the globe. The crop production on agricultural lands is squeezing due to aridity, climate change and low quality of irrigation water. The present study investigated the effect of biogenic silicon (Si) sources including wheat straw biochar (BC-ws), cotton stick biochar (BC-cs), rice husk feedstock (RH-fs), and sugarcane bagasse (SB), on the growth of two consecutive maize (Zea mays L.) crops in alkaline calcareous soil. The application of SB increased the photosynthetic rate, transpiration rate, stomatal conductance, and internal CO2 concentration by 104, 100, 55, and 16% in maize 1 and 140, 136, 76, and 22% in maize 2 respectively. Maximum yield (g/pot) of cob, straw, and root were remained as 39.5, 110.7, and 23.6 while 39.4, 113.2, and 23.6 in maize 1 and 2 respectively with the application of SB. The concentration of phosphorus (P) in roots, shoots, and cobs was increased by 157, 173, and 78% for maize 1 while 96, 224, and 161% for maize 2 respectively over control by applying SB. The plant cationic ratios (Mg:Na, Ca:Na, K:Na) were maximum in the SB applied treatment in maize 1 and 2. The study concluded that the application of SB on the basis of soluble Si, as a biogenic source, remained the best in alleviating the salt stress and enhancing the growth of maize in rotation. The field trials will be more interesting to recommend the farmer scale.

A TEMPO-oxidized cellulose nanofibers/MOFs hydrogel with temperature and pH responsiveness for fertilizers slow-release.

In this work, a kind of MOF MIL-100(Fe)@CNFs hydrogel (MC) based on TEMPO-oxidized cellulose nanofibers (CNFs) for fertilizers slow-release was prepared by free-radical polymerization, where N-vinyl caprolactam (NVCL) and CNFs were involved to exhibit temperature and pH response, respectively. Particularly, porous MIL-100(Fe), a kind of metal organic frameworks (MOFs), was introduced to optimize the load and slow-release capabilities. The Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis were used to characterize. The swelling behaviors and water-retention capabilities of hydrogels were evaluated. Using urea as the model fertilizer, the slow-release mechanism was revealed. Wheat was used as the model crop to evaluate the practical growth status. Compared with MC-0% hydrogels, the MC-10% hydrogels exhibited a better swelling capacity (37 g/g), water-retention (22.78%) and slow-release performance (40.84%). It also exhibited sensitivities to temperature and pH for regulating urea release. Besides, the number of tillers and leaves of wheat fertilized with MC hydrogels significantly increased, as did the photosynthetic rate. In conclusion, the MC-0% hydrogels had a positive influence on crops growth, and promoted the possible utilization of hydrogels in slow-release fertilizers.