Management of Nitrogen Flow in Livestock Waste System Towards an Efficient Circular Economy in Agriculture.

The race is on to achieve high level of efficiency in the attainment of circular economy in Agriculture especially with the aim of sustainable nitrogen management. This cycle in the agricultural sector cuts across livestock farming, agriculture induced waste generation, recycling and utilization, energy generation, crop production, ecosystem protection and environmental management through the mitigation of climate changes. In this work, we access the process and functionalities of livestock waste generated from the piggery farm and the combinations with other by-products such as biochar and ash in comparison with mineral fertilisation (MN) as sources of nitrogen (N) applied in agricultural soil. The experiment was performed in a controlled environment with wheat (Triticum aestivum L.) grown in a neutral and an acidic soil. Pig manure was used as the primary feedstock, fed, and processed to biogas and nutrient rich digestate by anaerobic digestion process. The digestate generated were amended with biochar and ash. In the course of the cultivation period, pig manure digestate with other co-amendments showed a positive influence on mobile potassium and phosphorus contents, biomass yield and nitrogen use efficiency. Greenhouse gas (GHG) emissions in the form of methane, carbon dioxide and nitrous oxide released in both soil types from the amendments were significantly lower when compared to mineral nitrogen treatment. The amendments did not have any significant influence on dehydrogenase activity, especially in the acid soil with the pH negatively influencing the enzymatic activities. The pig manure and pig manure digestate treatments showed positive response in the soil microbial biomass-C in the two soil types when compared to other co-amendments. Application of single use amendment application or in combination with biochar and ash as a means of waste management can enhance the N flow to meet up with crop needs, reduce GHG emissions and reduce potential agriculture’s negative environmental footprint.

Consumptive use pattern of mustard (Brassica Juncea L) under different soil and climatic environments

Mustard is an important cash crop in north India where it is widely grown under different climatic environment and soil types. In the present study, evapotranspiration and other agro-meteoralogical data for four agroclimatic locations, viz., Jorhat, Samakhunta, Raipur and Jodhpur have been utilized to understand consumptive use and related aspects of mustard. The evapotranspiration values recorded by lysimeters, global radiation and actual soil moisture data of Jorhat and the computed soil moisture have been used. The study suggests that the nlustard plant uses n10re water at all the stations except at humid location where consumptive use is least. The utilization is n1aximum betw~n 31-60 days after sowing in case ofJorhat l;er 111 and Samakhunta. The con1puted soil 1110isture estimates for 45 cm layer agree with the actual soil moisture. 15-1 The analysis also brings oUt that during the seventh week after sowing, the ratio of consumpiive use and rti. Ru Ilobal radiation attains a nlaxin1um value. This infonnation can be used for detennining irrigation needs and ular m computing energy balance components in the crop. ncymodsE..C.1..S.l.R...llC

Floods and their problems: Land uses and soil types perspectives

The phenomenon of flooding that occurs in almost all regions of the earth causes loss of property and damage to public facilities and causes the loss of many human lives. There are many reports related to the causes of flooding with various solutions offered to overcome the flood problem. However, it seems that these efforts have not been able to eliminate the flood problem. Hydrologists have widely reported various factors that are the cause of flooding with an extensive scope. Therefore, this paper is limited to discussing flooding and its problems, specifically the river flood, from the perspective of land use and soil types. Changes in land use in a watershed can cause an increase in the runoff coefficient. Likewise, different types of soil have different abilities in passing water into the ground. Open land (without land cover) tends to be prone to erosion, reducing the soil’s infiltration capacity and increased surface runoff. Increasing the runoff coefficient will increase the peak discharge in a watershed. The decrease in the river capacity due to sediment can cause a river flood. To support this argument, a rainfall-runoff model, particularly the tank model, is also discussed, taking into account the various uses and types of soil in a watershed. Efforts to anticipate the river flood are also considered for formulating flood disaster control policies in a watershed.

Sorption and Environmental Risks of Phosphorus in Subtropical Forest Soils

Phosphorus (P) is one of the key limiting factors for the growth of forests and their net primary productivity in subtropical forest ecosystems. Phosphorus leaching of the forest soil to the catchment and groundwater in karst region is the main source of water eutrophication. Strong P sorption capacity of minerals is generally assumed to be a key driver of P leaching in subtropical ecosystems which varies among different soil types. Here, we estimated P adsorption capacity of the O/A and AB horizon in both limestone soil and red soil of subtropical forests by fitting the Langmuir and Freundlich isotherm to investigate the potential environmental risks of P. The maximum P sorption capacity ( Q m ), P sorption constant ( K L ), P sorption index (PSI), degree of P saturation (DPS), and maximum buffer capacity (MBC) were calculated. The results indicate that Q m of the O/A horizon in both soils were similar. Comparing these two soils, the red soil had a higher K L and MBC in the AB horizon; Q m of limestone soil was larger but K L was lower, indicating that the adsorption capacity of limestone soil was weaker and MBC was lower. There was no significant difference in PSI between the two soils. The DPS values of both soils were below 1.1%, indicating that P saturation is low in both subtropical forest soils due to the lack of marked anthropogenic disturbance. In the O/A horizon, P saturation associated with available P (DPSM3 and DPSOlsen) and that associated with P in the Fe-Al bound state (DPScitrate) were higher in the red soil than in the limestone soil. DPS did not differ significantly in the AB horizon, except for higher DPSM3 and DPScitrate in the red soil. The findings highlight the influence of the soil types on P adsorption. The P adsorption and buffering of red soils were higher than those of limestone soils, indicating a lower risk of P leaching in red subtropical forest soils.

Mapping Soil Organic Matter and Analyzing the Prediction Accuracy of Typical Cropland Soil Types on the Northern Songnen Plain

Soil organic matter (SOM) plays a critical role in agroecosystems and the terrestrial carbon cycle. Thus, accurately mapping SOM promotes sustainable agriculture and estimations of soil carbon pools. However, few studies have analyzed the changing trends in multi-period SOM prediction accuracies for single cropland soil types and mapped their spatial SOM patterns. Using time series 7 MOD09A1 images during the bare soil period, we combined the pixel dates of training samples and precipitation data to explore the variation in SOM accuracy for two typical cropland soil types. The advantage of using single soil type data versus the total dataset was evaluated, and SOM maps were drawn for the northern Songnen Plain. When almost no precipitation occurred on or near the optimal pixel date, the accuracies increased, and vice versa. SOM models of the two soil types achieved a lower root mean squared error (RMSE = 0.55%, 0.79%) and mean absolute error (MAE = 0.39%, 0.58%) and a higher coefficient of determination (R2 = 0.65, 0.75) than the model using the total dataset and resulted in a mean relative improvement (RI) of 30.21%. The SOM decreased from northeast to southwest. The results provide reference data for the accurate management of cultivated soil and determining carbon sequestration.