Phosphorus (P) is the second most important macronutrient that limits the plant growth, development and productivity. Inorganic P fertilization in podzol soils predominantly bound with aluminum and iron, thereby reducing its availability to crop plants. Dairy manure (DM) amendment to agricultural soils can improve physiochemical properties, nutrient cycling through enhanced enzyme and soil microbial activities leading to improved P bioavailability to crops. We hypothesized that DM amendment in podzol soil will improve biochemical attributes and microbial community and abundance in silage corn cropping system under boreal climate. We evaluated the effects of organic and inorganic P amendments on soil biochemical attributes and abundance in podzol soil under boreal climate. Additionally, biochemical attributes and microbial population and abundance under short-term silage corn monocropping system was also investigated. Experimental treatments were [P₀ (control); P₁: DM with high P₂O₅; P₂: DM with low P₂O₅; P₃: inorganic P and five silage-corn genotypes (Fusion RR, Yukon R, A4177G3RIB, DKC 23-17RIB and DKC 26-28RIB) were laid out in a randomized complete block design in factorial settings with three replications. Results showed that P₁ treatment increased acid phosphatase (AP-ase) activity (29% and 44%), and soil available P (SAP) (60% and 39%) compared to control treatment, during 2016 and 2017, respectively. Additionally, P₁ treatments significantly increased total bacterial phospholipids fatty acids (ΣB-PLFA), total phospholipids fatty acids (ΣPLFA), fungi, and eukaryotes compared to control and inorganic P. Yukon R and DKC 26-28RIB genotypes exhibited higher total bacterial PLFA, fungi, and total PLFA in their rhizospheres compared to the other genotypes. Redundancy analyses showed promising association between P₁ and P₂ amendment, biochemical attributes and active microbial population and Yukon R and DKC 26-28RIB genotypes. Pearson correlation also demonstrated significant and positive correlation between AP-ase, SAP and gram negative bacteria (G⁻), fungi, ΣB-PLFA, and total PLFA. Study results demonstrated that P1 treatment enhanced biochemical attributes, active microbial community composition and abundance and forage production of silage corn. Results further demonstrated higher active microbial population and abundance in rhizosphere of Yukon R and DKC 26-28RIB genotypes. Therefore, we argue that dairy manure amendment with high P₂O₅ in podzol soils could be a sustainable nutrient source to enhance soil quality, health and forage production of silage corn. Yukon R and DKC 26-28RIB genotypes showed superior agronomic performance, therefore, could be good fit under boreal climatic conditions.

Intercropping (IC) is a promising approach used to improve soil health and sustainable crop production. However, it is unknown whether IC improve the soil health status and biomass productivity of crops cultivated in podzols under cool climate in boreal ecosystems. Two silage corn and three forage soybean genotypes were cultivated either as inter or monocrop (MC) treatments in a randomized complete block design. IC resulted in 28% increase in total forage production (FP). A reduction in rhizosphere soil pH (RS-pH) was observed in the IC treatments. Conversely, the rhizosphere soil acid phosphatase (RS-APase) activity was significantly higher (26–46%) in the IC treatments and occurred concomitant with a significant increase in available phosphorus (RS-P_available) (26–74%) in the rhizosphere. Furthermore, IC enhanced the active microbial composition and strong positive correlations were observed between RS-P_available, RS-APase, microbial biomass and FP; while RS-pH was negatively correlated with FP, RS-APase and RS-P_available. These findings suggested silage corn intercropped with forage soybean could be a viable approach to enhance FP through improved active microbial community structure, RS-APase activity and RS-P_available when cultivated on podzols in cool climate boreal ecosystem.

Plant roots are an integral part of soil ecosystems and contribute to various services, including carbon and nutrient cycling, weathering, and soil formation. They also modify soil physical properties (e.g., soil water content, pore size distribution, and bulk density) and impact subsequent crops’ growth. Cover crops have been reported to improve soil and environmental quality by reducing nutrient losses, improving soil water content, and increasing soil organic matter. Understanding the complex interactions between cover crop roots and soil (RS) is of utmost importance. However, cover crop RS interactions have not been critically reviewed. In this article, we investigated the nature of cover crop physical RS interactions and explored the emerging technologies for their study. We also assessed technologies that may be readily applied to the study of physical RS interactions in cover crop systems and discussed ways to improve related research in the future.

Dairy and livestock industry drives the economy and food security through sustainable supply of dairy products and meat across the globe. Dairy farm operations produce a large quantity of manure, which is a cheap and abundant plant nutrient source. However, insufficient forage production with low quality matrix are the current challenges of dairy industry in boreal climate due to extreme weather conditions. To address these challenges, a field experiment was conducted for three years to determine the effects of organic (dairy manure-based phosphorus (DMP)) and inorganic phosphorus (P) amendments on forage yield and quality indices of silage-corn cultivated in boreal climate. Experimental treatments were: (i) DMP with high P concentration (DMP1); (ii) DMP with low P concentration (DMP2) and (iii) inorganic P, also designated as control; and five silage-corn genotypes (Fusion-RR, Yukon-R, A4177G3-RIB, DKC23-17RIB, DKC26-28RIB). Results revealed that DMP1 amendment produced significantly higher forage yield compared to inorganic P, whereas non-significant effects were shown on quality indices except P mineral, available and crude protein. Yukon-R and DKC26-28RIB showed superior agronomic performance and produced significantly higher forage yield, whereas A4177G3-RIB produced lowest forage yield but exhibited superior nutritional quality; higher minerals, protein, total digestible nutrients, net energy for gain, net energy for maintenance and calculated milk production compared to other genotypes. Yukon-R not only produced higher forage, but also displayed good forage quality indices which were very close to A4177G3-RIB genotype. Therefore, we conclude that Yukon-R cultivation following DMP as organic amendment could be a sustainable production practice to attain high forage yield with optimum nutritional quality to meet the forage needs of growing dairy industry in boreal climate.