Effects of the Rapid Construction of a High-Quality Plough Layer Based on Woody Peat in a Newly Reclaimed Cultivated Land Area

To implement the balance system of cultivated land in occupation and supplement and to adhere to the principle of “supplement the occupied cultivated land of high quality with the one bearing same quality”, in the thesis, a field experiment was conducted to study the effects of woody peat on soil physical, chemical, and biological properties of the plough layer and its crop yield. Furthermore, the correlation between soil indexes and crop yield under the best fertilization mode through the addition of the natural material of woody peat instead of lengthy cultivation of the plough layer to rapidly construct a high-quality plough layer and solve the practical problem that the natural endowment of newly reclaimed cultivated land is far less than the occupied high-quality cultivated land was explored. The land remediation project of Fuping County, Hebei Province, was taken as the experimental area, and the five most representative and effective datasets were selected and studied. The results demonstrated that the addition of woody peat and rotten straw could reduce soil particle size and bulk density and alleviate soil viscosity and acidification. An increase in soil organic matter, soil microbial biomass carbon (MBC), alkali-hydrolyzable nitrogen, available phosphorus, and available potassium and a decrease in the heavy metal content were also observed. The results indicated that the application of woody peat achieved the expected effect of the rapid construction of a high-quality plough layer. The best mode of fertilization was A2, which provided a good reference for the rapid construction of a high-quality plough layer in the future. The analysis of the correlation between soil indexes and crop yield illustrated that the organic matter content, soil available nutrients, and crop yield had a significant positive correlation; the organic matter content and soil available nutrients showed the same tendency, which suggests that soil organic matter content and soil fertility level are closely related and that soil fertility plays a decisive role in crop yield under the same external conditions. Woody peat exerted an eminent influence on the organic matter content and soil available nutrients to determine the change in crop yield, which provides a reliable basis for future research on land improvement projects to increase crop yield.

Changes in soil exchangeable nutrients across different land uses in steep slopes of Mizoram, North-east India

Land use change resulting from anthropogenic pressure on land has led to degraded soil quality, especially in the hilly tropical regions where ecosystems are generally fragile and susceptible to soil degradation from cultivation. Hence, sustainable land uses and management practices are crucial for agricultural production and ecological balance, particularly in these regions. The present study investigates the impact of various hill land uses (Natural forest-NAF, Jhum fallow-JF, Home garden-HG, Acacia pennata plantation-AP and Current Jhum-CJ) on soil exchangeable nutrients in steeply sloping agro-ecosystems of Mizoram, North-east India. Soil samples were collected from three different depths (0-10, 10-20 & 20-30 cm) and analyzed for pH, Pavail, Na, K, Mg, Mn and Ca. Our results indicated that land use and soil depths had a significant impact on soil pH, Pavail and soil exchangeable cations (p<0.05). Conversion of native forests for cultivation negatively affected soil properties as indicated by the reduced soil exchangeable cations in cultivated lands (AP & CJ) in relation to the natural forest (NAF) and Jhum fallow (JF). Soils under longer periods of fallow (>12 years) led to increases in soil available nutrients indicating the role of vegetation cover in conserving and enhancing soil available nutrients and vice-versa. In addition, Home garden (HG) showed moderately higher available soil nutrients signifying the role of sustainable management practices such as the addition of organic amendments and mixed cropping, leading to increased soil available nutrient content.

Spatial Scale-Depended Characteristic Of Moss and Soil C, N, P and K Stoichiometry and Their Relationships In A Temperate Desert of Central Asia

Background and aims: Previous studies showed that moss stoichiometric characteristics were influenced by moss patch size and shrubs in desert. Study of moss stoichiometry in different spatial scales is crucial for understanding of growth and adaptation strategy of the mosses in temperate desert. Methods: In this study, the dominant moss (Syntrichia caninervis Mitt.) of biological soil crusts, and soil under the moss patches in the Gurbantunggut Desert were selected to determine their stoichiometry in different dunes and sites. Carbon (C), nitrogen (N), phosphorus (P) and potassium (K) contents of the moss and soil, and soil available nutrients were measured. Results: Moss stoichiometry and soil available nutrients were significantly influenced by changes in spatial distance scales except for moss C. The scaling exponents of moss N, P and K elements between above-ground and below-ground parts were 0.251, 0.389, 0.442, which were less than 1. The N vs. P scaling exponents were 0.71, 0.84 in above-ground and below-ground parts of moss. Moss C, P and K elements content in above-ground parts higher than that in below-ground parts. Moreover, moss N, P and K elements were influenced by MAP, longitude and soil nutrients. Conclusion: This study provided the C, N, P and K stoichiometric characteristics of desert moss and explored their relationships with environmental variables, which can help understand nutrient stoichiometry patterns and utilization strategy of N, P and K and their potential responses to global climate changes in the desert ecosystem of central Asia.