Estimates of Soil Renewal Rates: Applications for Anti-Erosion Arrangement of the Agricultural Landscape

: Engineering and geographic substantiation of the anti-erosion organization of agricultural landscapes requires not only di ﬀ erentiated estimations of erosion losses, but also commensurate (in terms of space–time scales) estimations of the soil loss tolerance. The main approaches for determining the participation of estimations of soil formation in the substantiation of erosion tolerance have been deﬁned. This study is aimed at justifying the methods of incorporating the results of pedogenesis modeling into computational methods for organizing agricultural landscapes. This paper presents the results of a study of the process of formation of the humus horizon and the accumulation of organic carbon in soils, based on soils from archaeological sites in the Crimean Peninsula over a period from 25 to 2000 years ago, with di ﬀ erences in climate and parent rock, in a region with a thousand-year history of human activity. The patterns of variation in the thickness of the humus horizons over time and the accumulation of carbon were determined, and estimates for the rate of the pedogenesis were obtained. In connection with the slowing of the rate of pedogenesis over time, the chronofunction of the change in the thickness of soils (of both exponential and logistic types) may be applied and, on this basis, it is possible to calculate the rates of the formation of the humus horizon depending on the morphological status of the soils. During re-naturation of highly degraded soils, maximum renewal rates may take place only with a very high input of organic matter, which is crucial to take into account in the development and implementation of programs for the rehabilitation of degraded lands. Under the conditions of slope agriculture, the rationale for T-values should be linked to many factors of the input and consumption of organic carbon, which provides a logical mathematical model of the formation of soil quality. For soil quality management on agricultural lands, a formula for calculating T-values, using an equation where the rate of pedogenesis is associated with a variety of changes in soil organic carbon, is proposed in this article.


Introduction
A ccord in g to m odern requirem ents for resource-saving land use, the land is considered n ot only as a m eans of production, bu t also as a significant part of the global pedosphere w hich fulfils the m ost im portant biosp heric and ecological functions. T he stand ard ization of soil erosion to the perm issible lim its o f red u ctio n o f th e top lay er is clo sely related to th e estim atio n s o f soil ren ew al rates, w h ich differ sig n ifican tly in in d iv id u al so il-clim atic region s. Soil loss to leran ce (also k n o w n b y "to lera n ce (tolerable) le v e l", "T -v alu e co n cep t (to lerab le soil lo ss )", or "e ro sio n to lera n ce"), 2. T = W tol. The rationale for such a value of sedim ent yield is that it does not lead to a significant reduction in crop yield s (W tol is tolerance soil loss).

Approaches and Methods for
Determining T-values Formulas Author V = H V -t , where VS is the maximum permissible value of soil erosion (mm year-1) and t is the number of years required to form a humus layer with a thickness of H mm Dolgilevich [2] 1. Identification of T-values with the rate of natural and/or anthropogenic soil formation, or as a direct function of these values. The tolerable value of soil wash-out is equal to the estimate in the process of natural soil formation of the average annual increase in humus horizons, expressed in fractions of a centimetre (or millimetre) per year.
2. Value of sediment yield, which does not lead to a significant reduction in crop yields.

T -D( A )•
where D is the intensity of soil erosion losses (t ha-1 year-1) and Ps is the soil thickness (m) Kirkby [3] which is formed due to the processes of weathering and soil formation. 3. Approaches in which the estimates of the rate of soil formation are included in the calculation methods for determining the T-values.
The formula for the most "acceptable" values of the decrease in the thickness of the soil.
The equation for defining the tolerable soil degradation at the point (x, y) at initial time (t).

T(x, y, 0 ------------T ^ _
where Tj is the soil renewal rate (mm year-1); T2 is the upper limit of allowable soil loss rate (mm year-1); Z is the present soil depth (m); Z2 is the minimum allowable soil depth; Z2 is the optimum soil depth; and n = 3.14 when calculating in radians (or from 0 to 180° for values in degrees).

Approaches and Methods for Determining T-values Formulas Author
Erosion tolerance level.
Calculation of the indicator for the lifespan of a soil.
10-T-values-y-C0- 10(1 + 0.01H) -H (ACar -ACmn -ACg) -C V « 0, where H is the thickness of the humus horizon (mm); C is the reserve of humus (Corg) in it (t ha-1); V is the rate of soil formation (mm year-1); T-values is the soil loss tolerance (mm year-1); ACar is the input component of the process of humus formation due to plant residues and fertilizers (t ha-1); ACmn is the mineralization of humus, which depends on the structure of crop rotation and yield level (t ha-1); ACg is the mineralization of passive humus (t ha-1); C0-w is the humus reserve in the washable layer (%); and у is the bulk density in the washable soil layer (t m-3). L _ 100(De -Do )y LF -Z-ZF , where Lf is the soil lifespan (years); Dg is the depth of available productive soil (cm); Do is the minimum soil depth for a particular crop (cm); y is the bulk mass of the soil (t m-3 ); Zf is the estimated rate of soil formation (t ha-1 year-1 ); and Z is the predicted rate of soil loss (t ha-1 year-1 ' T Indicator of the potential duration of the expenditure of soil with a constant average annual soil loss rate. Shvebs [5]; Lisetskii et al. [6] Elwell and Stocking [7] (with modifications)

Wy(Hi"-HW)
VE-Vf , where Hin is the initial (actual) thickness of the humus horizon (mm); Hw is the weighted average value of the optimum thickness of the humus horizon, taking into account the composition of crops in the crop rotation (mm); у is the bulk density of the soil (t m-3); and VE and Vf are the average perennial (or justified in the proportional availability) rates of erosion and soil formation, respectively (t ha-1 ).
Lisetskii et al. [8] In W estern E u rop e and N o rth A m erica, w h en an aly zin g approach es to m o d elin g w ater erosion processes, eith er tw o - [9 ] or th ree-lev el [10] cla ssificatio n is used. W ith in the specified classes and The soils form ed in extra-glacial regions have a long history of developm ent (over approxim ately the last 11,500 y ears) [11]. T he "u n fo ld in g " o f the p ed o g en esis h isto ry u sin g the g eo arch aeo lo gical ap p roach has g reat in fo rm atio n al p o ten tial;  [12][13][14]. M oreover, u n lik e the first three decades, from 2000 to present [15][16][17], there has been an accelerated grow th in the num ber of scientific publications. These papers used new geoarchaeological m ethods in the research of soils and sedim ents at archaeological sites [18][19][20][21][22][23][24][25]. T h e aim o f this stu d y is to su bstan tiate th e w ays o f in teg ratin g p ed o ch ro n olo g ical d ata and estim ates of the rate of soil form ation into com putational m ethods for arranging agricultural landscapes.

M aterial and M ethods
T he soil cover of the C rim ean Peninsula (Figure 1) is represented b y various types and sub-types (m ore th an 50 species) o f soil, th e p red om in an t types b ein g C alcic C h ern o zem an d P etro calcic C hernozem [32] . The south coast of C rim ea (SCC) exhibits a rem arkable variety of soil types on various substrates; m ainly Su b-M editerranean cinnam onic soils and red types [33]. C alcaric C am bisols (IUSS W orking G roup W R B 2014) or, according to the nom enclature of C rim ean soils, the cinnam onic forest soils, occur on the southern slope of the M ain R id ge and in the foothills w est and east of it.
These specific features determ ined the choice of four areas for our pedoarchaeological field studies ( Figure 1).  To process the data, w e used the softw are prod uct Statistica A dvan ced + QC for W ind ow s v.10.

The Clim atic Features o f the Study A rea
T h e clim atic p aram eters w ere tak en from th e region al referen ce b o o k [4 0 ] on m eteo ro log ical stations, w hich characterizes the specific features of individual regions in the first polygon of the study area (Yevpatoria (West), Kerch (East), and Sim feropol (South)) and in the second polygon of the study area (Yalta) ( Table 2). These data w ere used for the evaluation of energy expenses on soil form ation (Q ).
W h en w e introd u ced these to the form u la fou n d in R eferen ce [41], co n v ertin g the rad iatio n b alan ce v alu es to an in tern atio n al system o f u n it m ea su rem en t v a lu es (co n v ersio n o f calo ries in to jo u les), the calcu lation form ula for the v alu e of Q (MJ/(m2-year)) w as m odified into the follow ing form: w here R is the radiation balance (MJ/(m2-year)) and P is the annual rainfall (mm).     The process of soil developm ent over tim e can be adequately described using the S-shaped curve fam ily; in particular, u sing the G om pertz function:

Sum m arized Rates o f Soil Form ation
A nalysis of the G om pertz function gives valuable inform ation on the regularities of pedogenesis.   Table 2 [69]. At the initial stages of pedogenesis, w hen the highest renew al rates are observed, there occurs a replacem ent "e co sy stem a ttra c to r", w h ich con trols the p ro cess o f a ccu m u latio n o f SO C , in situ, in the la y er of m axim u m d ev elo p m en t o f th e p aren t ro ck b y th e biota, a "clim a tic a ttra cto r" [70]. For C h ern ozem s, this replacem ent occurs after 7 0 -170 years, w hen the soil reaches the first 1 5 -2 0 cm of thickness of the hum us horizon [71].

Regional Chronofunctions of Changes of the Humus Horizon
Field stud ies in 2016 p erm itted us to o b tain n ew resu lts, b y stu d yin g calca ric C am b iso ls a t archaeological sites for the SC C territory w ith su b-M ed iterran ean con d ition s (Table 3) .   T h e d ata in Table 3  A s sh o w n earlier [35,72], in the; ch ron o log ical series o f the calcaric C am b iso ls, th e h u m u s co n ten t in the upper1 h orieon increases w ith kge, from 4.1% to 7 .0 -9 .t% . A significant hum us accum ulktion w as obserced in soils aged at only several centuries (Table 3 ). Subseauently, this rate of hum us accum ulatiob decreased. D urin g the H olocen c, soil evolution in the cinnam onic soils z one of south w estern C rim ea w as m arked by active hum us accum ulation (about 0.04'%/100 year), as w ell as an enrichm ent in niirogen of the hum ue [72]. A ccord ing to Table 3

Stages o f E ngineering and G eographical A rrangem ent o f the A gricu ltural Landscape
The engineering and landscape substantiation of geo-planning (landscaping and land use) allows including estim ates of the rates of destruction, reproduction, and qu ality of the soil (see approach 3 in Table 1). im ages from G oogle Earth [74], or from other sim ilar services. H ow ever, the task is to use these results for an environm entally friendly and resou rce-saving landscape, for lean and responsible land use.

The D eterm ine o f T-values fo r A gricultural Landscapes
It is clear that the estim ates for the rate of form ation of the hum us horizon should receive a m ore In general, the balance equation of the process of hum us form ation, w h ich reflects the ch an ge in the com p onents of the balance over one year, m ay b e w ritten as follow s: ACa + ACb + ACc + A Q + ACq + ACpz + ACns + ACm + ACS = ACp + ACmn + AC; -z + ACe + ACz + ACg ± AC (4) w here the input of hum us (t ha-1 ) is provided by the follow ing sources: the remains of agricultural crops It m ay be presented in the form of the follow in g com ponents: w here A and D are the am ounts of plant residues and organic fertilizers (t h a-1 ), respectively; K 'h and and ^ is the nitrogen con tent in the seed m aterial (%; the average for cereals is 1 .6 %).  -1 ); Cp is the h u m u s co n ten t in th e w ash ab le soil la y er (% ); C and Co-10 are the hum us reserves in the hum us horizon and the w ashable soil layer, respectively (t h a-1 ); V is the rate of soil form ation (mm y ear-1 ); у is the bulk density in the w ashable soil layer (t m -3 ); and k is the coefficient of excess of hum us con ten t in the solid sink, w ith respect to the original value.
T his so lu tio n is less accu rate th an (E q u atio n s (4) an d (5)) b u t is su itab le fo r p ractical u se in SQ

Use o f P edochronological D ata f o r Land Restoration and Soil Q uality
The state of a soil system m ay be described either by in p u t  (Table 4 ).  T h e problem o f soil co n tam in atio n w ith h eav y m etals arises, ev en w h en u sin g co n v en tion al m ineral fertilizers [83].

C onclusions
T h is stu d y h as show n th a t an ad ap tiv e lan d scap e ap p roach to the g eo -